character assignment in java

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Class Character

• java.lang.Object
• java.lang.Character

Unicode Conformance

Unicode character representations, nested class summary, field summary, constructor summary, method summary, methods inherited from class java.lang. object, field detail, uppercase_letter, lowercase_letter, titlecase_letter, modifier_letter, other_letter, non_spacing_mark, enclosing_mark, combining_spacing_mark, decimal_digit_number, letter_number, other_number, space_separator, line_separator, paragraph_separator, private_use, dash_punctuation, start_punctuation, end_punctuation, connector_punctuation, other_punctuation, math_symbol, currency_symbol, modifier_symbol, other_symbol, initial_quote_punctuation, final_quote_punctuation, directionality_undefined, directionality_left_to_right, directionality_right_to_left, directionality_right_to_left_arabic, directionality_european_number, directionality_european_number_separator, directionality_european_number_terminator, directionality_arabic_number, directionality_common_number_separator, directionality_nonspacing_mark, directionality_boundary_neutral, directionality_paragraph_separator, directionality_segment_separator, directionality_whitespace, directionality_other_neutrals, directionality_left_to_right_embedding, directionality_left_to_right_override, directionality_right_to_left_embedding, directionality_right_to_left_override, directionality_pop_directional_format, min_high_surrogate, max_high_surrogate, min_low_surrogate, max_low_surrogate, min_surrogate, max_surrogate, min_supplementary_code_point, min_code_point, max_code_point, constructor detail, method detail, isvalidcodepoint, isbmpcodepoint, issupplementarycodepoint, ishighsurrogate, islowsurrogate, issurrogate, issurrogatepair.

isHighSurrogate(high) && isLowSurrogate(low)

toCodePoint

Codepointat, codepointbefore, highsurrogate, lowsurrogate, codepointcount, offsetbycodepoints, islowercase.

a b c d e f g h i j k l m n o p q r s t u v w x y z '\u00DF' '\u00E0' '\u00E1' '\u00E2' '\u00E3' '\u00E4' '\u00E5' '\u00E6' '\u00E7' '\u00E8' '\u00E9' '\u00EA' '\u00EB' '\u00EC' '\u00ED' '\u00EE' '\u00EF' '\u00F0' '\u00F1' '\u00F2' '\u00F3' '\u00F4' '\u00F5' '\u00F6' '\u00F8' '\u00F9' '\u00FA' '\u00FB' '\u00FC' '\u00FD' '\u00FE' '\u00FF'

isUpperCase

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z '\u00C0' '\u00C1' '\u00C2' '\u00C3' '\u00C4' '\u00C5' '\u00C6' '\u00C7' '\u00C8' '\u00C9' '\u00CA' '\u00CB' '\u00CC' '\u00CD' '\u00CE' '\u00CF' '\u00D0' '\u00D1' '\u00D2' '\u00D3' '\u00D4' '\u00D5' '\u00D6' '\u00D8' '\u00D9' '\u00DA' '\u00DB' '\u00DC' '\u00DD' '\u00DE'

isTitleCase

• '\uFF10' through '\uFF19' , Fullwidth digits Many other character ranges contain digits as well. Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character is a digit; false otherwise. Since: 1.5 See Also: forDigit(int, int) , getType(int)
• It has a value in a range defined by the UnicodeData file. Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character has a defined meaning in Unicode; false otherwise. Since: 1.5 See Also: isDigit(int) , isLetter(int) , isLetterOrDigit(int) , isLowerCase(int) , isTitleCase(int) , isUpperCase(int)
• OTHER_LETTER Not all letters have case. Many characters are letters but are neither uppercase nor lowercase nor titlecase. Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character is a letter; false otherwise. Since: 1.5 See Also: isDigit(int) , isJavaIdentifierStart(int) , isLetterOrDigit(int) , isLowerCase(int) , isTitleCase(int) , isUnicodeIdentifierStart(int) , isUpperCase(int)

isLetterOrDigit

Isjavaletter.

• ch is a connecting punctuation character (such as '_' ). These conditions are tested against the character information from version 6.2 of the Unicode Standard. Parameters: ch - the character to be tested. Returns: true if the character may start a Java identifier; false otherwise. Since: 1.02 See Also: isJavaLetterOrDigit(char) , isJavaIdentifierStart(char) , isJavaIdentifierPart(char) , isLetter(char) , isLetterOrDigit(char) , isUnicodeIdentifierStart(char)

isJavaLetterOrDigit

• isIdentifierIgnorable returns true for the character. These conditions are tested against the character information from version 6.2 of the Unicode Standard. Parameters: ch - the character to be tested. Returns: true if the character may be part of a Java identifier; false otherwise. Since: 1.02 See Also: isJavaLetter(char) , isJavaIdentifierStart(char) , isJavaIdentifierPart(char) , isLetter(char) , isLetterOrDigit(char) , isUnicodeIdentifierPart(char) , isIdentifierIgnorable(char)

isAlphabetic

• LETTER_NUMBER or it has contributory property Other_Alphabetic as defined by the Unicode Standard. Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character is a Unicode alphabet character, false otherwise. Since: 1.7

isIdeographic

Isjavaidentifierstart.

• the referenced character is a connecting punctuation character (such as '_' ). These conditions are tested against the character information from version 6.2 of the Unicode Standard. Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character may start a Java identifier; false otherwise. Since: 1.5 See Also: isJavaIdentifierPart(int) , isLetter(int) , isUnicodeIdentifierStart(int) , SourceVersion.isIdentifier(CharSequence)

isJavaIdentifierPart

• isIdentifierIgnorable(codePoint) returns true for the code point These conditions are tested against the character information from version 6.2 of the Unicode Standard. Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character may be part of a Java identifier; false otherwise. Since: 1.5 See Also: isIdentifierIgnorable(int) , isJavaIdentifierStart(int) , isLetterOrDigit(int) , isUnicodeIdentifierPart(int) , SourceVersion.isIdentifier(CharSequence)

isUnicodeIdentifierStart

• getType(codePoint) returns LETTER_NUMBER . Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character may start a Unicode identifier; false otherwise. Since: 1.5 See Also: isJavaIdentifierStart(int) , isLetter(int) , isUnicodeIdentifierPart(int)

isUnicodeIdentifierPart

• isIdentifierIgnorable returns true for this character. Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character may be part of a Unicode identifier; false otherwise. Since: 1.5 See Also: isIdentifierIgnorable(int) , isJavaIdentifierPart(int) , isLetterOrDigit(int) , isUnicodeIdentifierStart(int)

isIdentifierIgnorable

• all characters that have the FORMAT general category value Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character is an ignorable control character that may be part of a Java or Unicode identifier; false otherwise. Since: 1.5 See Also: isJavaIdentifierPart(int) , isUnicodeIdentifierPart(int)

toLowerCase

Touppercase, totitlecase.

• The character is one of the fullwidth lowercase Latin letters a ( '\uFF41' ) through z ( '\uFF5A' ) and its code is less than radix + '\uFF41'- 10 . In this case, codePoint - '\uFF41' + 10 is returned. Parameters: codePoint - the character (Unicode code point) to be converted. radix - the radix. Returns: the numeric value represented by the character in the specified radix. Since: 1.5 See Also: forDigit(int, int) , isDigit(int)

getNumericValue

Isspacechar.

• PARAGRAPH_SEPARATOR Parameters: codePoint - the character (Unicode code point) to be tested. Returns: true if the character is a space character; false otherwise. Since: 1.5 See Also: isWhitespace(int)

isWhitespace

Isisocontrol, getdirectionality, reversebytes.

Character.UnicodeBlock.of(codePoint).toString().replace('_', ' ') + " " + Integer.toHexString(codePoint).toUpperCase(Locale.ENGLISH);

Submit a bug or feature For further API reference and developer documentation, see Java SE Documentation . That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples. Copyright © 1993, 2024, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms . Also see the documentation redistribution policy .

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Assignment operator in Java

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Assignment operators in java: an overview.

We already discussed the Types of Operators in the previous tutorial Java. In this Java tutorial , we will delve into the different types of assignment operators in Java, and their syntax, and provide examples for better understanding. Because Java is a flexible and widely used programming language. Assignment operators play a crucial role in manipulating and assigning values to variables. To further enhance your understanding and application of Java assignment operator's concepts, consider enrolling in the best Java Certification Course .

What are the Assignment Operators in Java?

Assignment operators in Java are used to assign values to variables . They are classified into two main types: simple assignment operator and compound assignment operator.

The general syntax for a simple assignment statement is:

And for a compound assignment statement:

Read More - Advanced Java Interview Questions

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Types of Assignment Operators in Java

• Simple Assignment Operator: The Simple Assignment Operator is used with the "=" sign, where the operand is on the left side and the value is on the right. The right-side value must be of the same data type as that defined on the left side.
• Compound Assignment Operator:  Compound assignment operators combine arithmetic operations with assignments. They provide a concise way to perform an operation and assign the result to the variable in one step. The Compound Operator is utilized when +,-,*, and / are used in conjunction with the = operator.

1. Simple Assignment Operator (=):

The equal sign (=) is the basic assignment operator in Java. It is used to assign the value on the right-hand side to the variable on the left-hand side.

Explanation

2. addition assignment operator (+=) :, 3. subtraction operator (-=):, 4. multiplication operator (*=):.

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5. Division Operator (/=):

6. modulus assignment operator (%=):, example of assignment operator in java.

Let's look at a few examples in our Java Playground to illustrate the usage of assignment operators in Java:

• Unary Operator in Java
• Arithmetic Operators in Java
• Relational Operators in Java
• Logical Operators in Java
• Ternary Operator in Java

Q1. Can I use multiple assignment operators in a single statement?

Q2. are there any other compound assignment operators in java, q3. how many types of assignment operators.

• 1. (=) operator
• 1. (+=) operator
• 2. (-=) operator
• 3. (*=) operator
• 4. (/=) operator
• 5. (%=) operator

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1.4. Expressions and Assignment Statements ¶

In this lesson, you will learn about assignment statements and expressions that contain math operators and variables.

1.4.1. Assignment Statements ¶

Remember that a variable holds a value that can change or vary. Assignment statements initialize or change the value stored in a variable using the assignment operator = . An assignment statement always has a single variable on the left hand side of the = sign. The value of the expression on the right hand side of the = sign (which can contain math operators and other variables) is copied into the memory location of the variable on the left hand side.

Figure 1: Assignment Statement (variable = expression) ¶

Instead of saying equals for the = operator in an assignment statement, say “gets” or “is assigned” to remember that the variable on the left hand side gets or is assigned the value on the right. In the figure above, score is assigned the value of 10 times points (which is another variable) plus 5.

The following video by Dr. Colleen Lewis shows how variables can change values in memory using assignment statements.

As we saw in the video, we can set one variable to a copy of the value of another variable like y = x;. This won’t change the value of the variable that you are copying from.

Click on the Show CodeLens button to step through the code and see how the values of the variables change.

The program is supposed to figure out the total money value given the number of dimes, quarters and nickels. There is an error in the calculation of the total. Fix the error to compute the correct amount.

Calculate and print the total pay given the weekly salary and the number of weeks worked. Use string concatenation with the totalPay variable to produce the output Total Pay = $3000 . Don’t hardcode the number 3000 in your print statement.

Assume you have a package with a given height 3 inches and width 5 inches. If the package is rotated 90 degrees, you should swap the values for the height and width. The code below makes an attempt to swap the values stored in two variables h and w, which represent height and width. Variable h should end up with w’s initial value of 5 and w should get h’s initial value of 3. Unfortunately this code has an error and does not work. Use the CodeLens to step through the code to understand why it fails to swap the values in h and w.

1-4-7: Explain in your own words why the ErrorSwap program code does not swap the values stored in h and w.

Swapping two variables requires a third variable. Before assigning h = w , you need to store the original value of h in the temporary variable. In the mixed up programs below, drag the blocks to the right to put them in the right order.

The following has the correct code that uses a third variable named “temp” to swap the values in h and w.

The code is mixed up and contains one extra block which is not needed in a correct solution. Drag the needed blocks from the left into the correct order on the right, then check your solution. You will be told if any of the blocks are in the wrong order or if you need to remove one or more blocks.

After three incorrect attempts you will be able to use the Help Me button to make the problem easier.

Fix the code below to perform a correct swap of h and w. You need to add a new variable named temp to use for the swap.

1.4.2. Incrementing the value of a variable ¶

If you use a variable to keep score you would probably increment it (add one to the current value) whenever score should go up. You can do this by setting the variable to the current value of the variable plus one (score = score + 1) as shown below. The formula looks a little crazy in math class, but it makes sense in coding because the variable on the left is set to the value of the arithmetic expression on the right. So, the score variable is set to the previous value of score + 1.

Click on the Show CodeLens button to step through the code and see how the score value changes.

1-4-11: What is the value of b after the following code executes?

• It sets the value for the variable on the left to the value from evaluating the right side. What is 5 * 2?
• Correct. 5 * 2 is 10.

1-4-12: What are the values of x, y, and z after the following code executes?

• x = 0, y = 1, z = 2
• These are the initial values in the variable, but the values are changed.
• x = 1, y = 2, z = 3
• x changes to y's initial value, y's value is doubled, and z is set to 3
• x = 2, y = 2, z = 3
• Remember that the equal sign doesn't mean that the two sides are equal. It sets the value for the variable on the left to the value from evaluating the right side.
• x = 1, y = 0, z = 3

1.4.3. Operators ¶

Java uses the standard mathematical operators for addition ( + ), subtraction ( - ), multiplication ( * ), and division ( / ). Arithmetic expressions can be of type int or double. An arithmetic operation that uses two int values will evaluate to an int value. An arithmetic operation that uses at least one double value will evaluate to a double value. (You may have noticed that + was also used to put text together in the input program above – more on this when we talk about strings.)

Java uses the operator == to test if the value on the left is equal to the value on the right and != to test if two items are not equal. Don’t get one equal sign = confused with two equal signs == ! They mean different things in Java. One equal sign is used to assign a value to a variable. Two equal signs are used to test a variable to see if it is a certain value and that returns true or false as you’ll see below. Use == and != only with int values and not doubles because double values are an approximation and 3.3333 will not equal 3.3334 even though they are very close.

Run the code below to see all the operators in action. Do all of those operators do what you expected? What about 2 / 3 ? Isn’t surprising that it prints 0 ? See the note below.

When Java sees you doing integer division (or any operation with integers) it assumes you want an integer result so it throws away anything after the decimal point in the answer, essentially rounding down the answer to a whole number. If you need a double answer, you should make at least one of the values in the expression a double like 2.0.

With division, another thing to watch out for is dividing by 0. An attempt to divide an integer by zero will result in an ArithmeticException error message. Try it in one of the active code windows above.

Operators can be used to create compound expressions with more than one operator. You can either use a literal value which is a fixed value like 2, or variables in them. When compound expressions are evaluated, operator precedence rules are used, so that *, /, and % are done before + and -. However, anything in parentheses is done first. It doesn’t hurt to put in extra parentheses if you are unsure as to what will be done first.

In the example below, try to guess what it will print out and then run it to see if you are right. Remember to consider operator precedence .

1-4-15: Consider the following code segment. Be careful about integer division.

What is printed when the code segment is executed?

• 0.666666666666667
• Don't forget that division and multiplication will be done first due to operator precedence.
• Yes, this is equivalent to (5 + ((a/b)*c) - 1).
• Don't forget that division and multiplication will be done first due to operator precedence, and that an int/int gives an int result where it is rounded down to the nearest int.

1-4-16: Consider the following code segment.

What is the value of the expression?

• Dividing an integer by an integer results in an integer
• Correct. Dividing an integer by an integer results in an integer
• The value 5.5 will be rounded down to 5

1-4-17: Consider the following code segment.

• Correct. Dividing a double by an integer results in a double
• Dividing a double by an integer results in a double

1-4-18: Consider the following code segment.

• Correct. Dividing an integer by an double results in a double
• Dividing an integer by an double results in a double

1.4.4. The Modulo Operator ¶

The percent sign operator ( % ) is the mod (modulo) or remainder operator. The mod operator ( x % y ) returns the remainder after you divide x (first number) by y (second number) so 5 % 2 will return 1 since 2 goes into 5 two times with a remainder of 1. Remember long division when you had to specify how many times one number went into another evenly and the remainder? That remainder is what is returned by the modulo operator.

Figure 2: Long division showing the whole number result and the remainder ¶

In the example below, try to guess what it will print out and then run it to see if you are right.

The result of x % y when x is smaller than y is always x . The value y can’t go into x at all (goes in 0 times), since x is smaller than y , so the result is just x . So if you see 2 % 3 the result is 2 .

1-4-21: What is the result of 158 % 10?

• This would be the result of 158 divided by 10. modulo gives you the remainder.
• modulo gives you the remainder after the division.
• When you divide 158 by 10 you get a remainder of 8.

1-4-22: What is the result of 3 % 8?

• 8 goes into 3 no times so the remainder is 3. The remainder of a smaller number divided by a larger number is always the smaller number!
• This would be the remainder if the question was 8 % 3 but here we are asking for the reminder after we divide 3 by 8.
• What is the remainder after you divide 3 by 8?

1.4.5. FlowCharting ¶

Assume you have 16 pieces of pizza and 5 people. If everyone gets the same number of slices, how many slices does each person get? Are there any leftover pieces?

In industry, a flowchart is used to describe a process through symbols and text. A flowchart usually does not show variable declarations, but it can show assignment statements (drawn as rectangle) and output statements (drawn as rhomboid).

The flowchart in figure 3 shows a process to compute the fair distribution of pizza slices among a number of people. The process relies on integer division to determine slices per person, and the mod operator to determine remaining slices.

Figure 3: Example Flow Chart ¶

A flowchart shows pseudo-code, which is like Java but not exactly the same. Syntactic details like semi-colons are omitted, and input and output is described in abstract terms.

Complete the program based on the process shown in the Figure 3 flowchart. Note the first line of code declares all 4 variables as type int. Add assignment statements and print statements to compute and print the slices per person and leftover slices. Use System.out.println for output.

1.4.6. Storing User Input in Variables ¶

Variables are a powerful abstraction in programming because the same algorithm can be used with different input values saved in variables.

Figure 4: Program input and output ¶

A Java program can ask the user to type in one or more values. The Java class Scanner is used to read from the keyboard input stream, which is referenced by System.in . Normally the keyboard input is typed into a console window, but since this is running in a browser you will type in a small textbox window displayed below the code. The code below shows an example of prompting the user to enter a name and then printing a greeting. The code String name = scan.nextLine() gets the string value you enter as program input and then stores the value in a variable.

Run the program a few times, typing in a different name. The code works for any name: behold, the power of variables!

Run this program to read in a name from the input stream. You can type a different name in the input window shown below the code.

Try stepping through the code with the CodeLens tool to see how the name variable is assigned to the value read by the scanner. You will have to click “Hide CodeLens” and then “Show in CodeLens” to enter a different name for input.

The Scanner class has several useful methods for reading user input. A token is a sequence of characters separated by white space.

Run this program to read in an integer from the input stream. You can type a different integer value in the input window shown below the code.

A rhomboid (slanted rectangle) is used in a flowchart to depict data flowing into and out of a program. The previous flowchart in Figure 3 used a rhomboid to indicate program output. A rhomboid is also used to denote reading a value from the input stream.

Figure 5: Flow Chart Reading User Input ¶

Figure 5 contains an updated version of the pizza calculator process. The first two steps have been altered to initialize the pizzaSlices and numPeople variables by reading two values from the input stream. In Java this will be done using a Scanner object and reading from System.in.

Complete the program based on the process shown in the Figure 5 flowchart. The program should scan two integer values to initialize pizzaSlices and numPeople. Run the program a few times to experiment with different values for input. What happens if you enter 0 for the number of people? The program will bomb due to division by zero! We will see how to prevent this in a later lesson.

The program below reads two integer values from the input stream and attempts to print the sum. Unfortunately there is a problem with the last line of code that prints the sum.

Run the program and look at the result. When the input is 5 and 7 , the output is Sum is 57 . Both of the + operators in the print statement are performing string concatenation. While the first + operator should perform string concatenation, the second + operator should perform addition. You can force the second + operator to perform addition by putting the arithmetic expression in parentheses ( num1 + num2 ) .

More information on using the Scanner class can be found here https://www.w3schools.com/java/java_user_input.asp

1.4.7. Programming Challenge : Dog Years ¶

In this programming challenge, you will calculate your age, and your pet’s age from your birthdates, and your pet’s age in dog years. In the code below, type in the current year, the year you were born, the year your dog or cat was born (if you don’t have one, make one up!) in the variables below. Then write formulas in assignment statements to calculate how old you are, how old your dog or cat is, and how old they are in dog years which is 7 times a human year. Finally, print it all out.

Calculate your age and your pet’s age from the birthdates, and then your pet’s age in dog years. If you want an extra challenge, try reading the values using a Scanner.

1.4.8. Summary ¶

Arithmetic expressions include expressions of type int and double.

The arithmetic operators consist of +, -, * , /, and % (modulo for the remainder in division).

An arithmetic operation that uses two int values will evaluate to an int value. With integer division, any decimal part in the result will be thrown away, essentially rounding down the answer to a whole number.

An arithmetic operation that uses at least one double value will evaluate to a double value.

Operators can be used to construct compound expressions.

During evaluation, operands are associated with operators according to operator precedence to determine how they are grouped. (*, /, % have precedence over + and -, unless parentheses are used to group those.)

An attempt to divide an integer by zero will result in an ArithmeticException to occur.

The assignment operator (=) allows a program to initialize or change the value stored in a variable. The value of the expression on the right is stored in the variable on the left.

During execution, expressions are evaluated to produce a single value.

The value of an expression has a type based on the evaluation of the expression.

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Character Variable in Java Programming

Java basic concepts.

In this lesson, we will learn about Character variable in Java programming with the help of some examples. We will also play a quiz on it at the end.

What is Character Variable

A Character variable in Java programming can store any character enclosed within single quotes. To declare a variable of type character we use the keyword char (pronounced as kar).

Syntax of Declaring Character Variable in Java

Here char is used for declaring Character data type and variable_name is the name of variable (you can use any name of your choice for example: a, b, c, alpha, etc.) and ; is used for line terminator (end of line).

Now let's see some examples for more understanding.

Declare a character variable x .

Declare 3 character variables x , y , and z to assign 3 different characters in it.

Note: A character can be anything, it can be an alphabet or digit or any other symbol, but it must be single in quantity.

Declare a character variable x and assign the character '$' and change it value to @ in the next line.

Test Your Knowledge

Attempt the multiple choice quiz to check if the lesson is adequately clear to you.

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Java Tutorials

Java String equals()

Java String intern()

Java String compareTo()

• Java String concat()

Java String equalsIgnoreCase()

• Java String compareToIgnoreCase()

In Java, a string is a sequence of characters. For example, "hello" is a string containing a sequence of characters 'h' , 'e' , 'l' , 'l' , and 'o' .

We use double quotes to represent a string in Java. For example,

Here, we have created a string variable named type . The variable is initialized with the string Java Programming .

Example: Create a String in Java

In the above example, we have created three strings named first , second , and third .

Here, we are directly creating strings like primitive types .

However, there is another way of creating Java strings (using the new keyword).

We will learn about that later in this tutorial.

Note : Strings in Java are not primitive types (like int , char , etc). Instead, all strings are objects of a predefined class named String .

And all string variables are instances of the String class.

Java String Operations

Java provides various string methods to perform different operations on strings. We will look into some of the commonly used string operations.

1. Get the Length of a String

To find the length of a string, we use the length() method. For example,

In the above example, the length() method calculates the total number of characters in the string and returns it.

To learn more, visit Java String length() .

2. Join Two Java Strings

We can join two strings in Java using the concat() method. For example,

In the above example, we have created two strings named first and second . Notice the statement,

Here, the concat() method joins the second string to the first string and assigns it to the joinedString variable.

We can also join two strings using the + operator in Java.

To learn more, visit Java String concat() .

3. Compare Two Strings

In Java, we can make comparisons between two strings using the equals() method. For example,

In the above example, we have created 3 strings named first , second , and third .

Here, we are using the equal() method to check if one string is equal to another.

The equals() method checks the content of strings while comparing them. To learn more, visit Java String equals() .

Note : We can also compare two strings using the == operator in Java. However, this approach is different than the equals() method. To learn more, visit Java String == vs equals() .

Escape Character in Java Strings

The escape character is used to escape some of the characters present inside a string.

Suppose we need to include double quotes inside a string.

Since strings are represented by double quotes , the compiler will treat "This is the " as the string. Hence, the above code will cause an error.

To solve this issue, we use the escape character \ in Java. For example,

Now escape characters tell the compiler to escape double quotes and read the whole text.

Java Strings are Immutable

In Java, strings are immutable . This means once we create a string, we cannot change that string.

To understand it more thoroughly, consider an example:

Here, we have created a string variable named example . The variable holds the string "Hello! " .

Now, suppose we want to change the string.

Here, we are using the concat() method to add another string "World" to the previous string.

It looks like we are able to change the value of the previous string. However, this is not true .

Let's see what has happened here:

• JVM takes the first string "Hello! "
• creates a new string by adding "World" to the first string
• assigns the new string "Hello! World" to the example variable
• The first string "Hello! " remains unchanged

Creating Strings Using the New Keyword

So far, we have created strings like primitive types in Java.

Since strings in Java are objects, we can create strings using the new keyword as well. For example,

In the above example, we have created a string name using the new keyword.

Here, when we create a string object, the String() constructor is invoked.

To learn more about constructors, visit Java Constructor .

Note : The String class provides various other constructors to create strings. To learn more, visit Java String (official Java documentation) .

Example: Create Java Strings Using the New Keyword

Create string using literals vs. new keyword.

Now that we know how strings are created using string literals and the new keyword, let's see what is the major difference between them.

In Java, the JVM maintains a string pool to store all of its strings inside the memory. The string pool helps in reusing the strings.

1. While creating strings using string literals,

Here, we are directly providing the value of the string ( Java ). Hence, the compiler first checks the string pool to see if the string already exists.

• If the string already exists , the new string is not created. Instead, the new reference, example points to the already existing string ( Java ).
• If the string doesn't exist , a new string ( Java) is created.

2. While creating strings using the new keyword,

Here, the value of the string is not directly provided. Hence, a new "Java" string is created even though "Java" is already present inside the memory pool.

• Methods of Java String

Besides those mentioned above, there are various string methods present in Java. Here are some of those methods:

Table of Contents

• Java String
• Create a String in Java
• Get Length of a String
• Join two Strings
• Compare two Strings
• Escape character in Strings
• Immutable Strings
• Creating strings using the new keyword
• String literals vs new keyword

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Related Tutorials

Java Library

Improving OpenJDK Scalar Replacement – Part 1/3

Cesar Soares

May 28th, 2024 0 2

Scalar replacement (SR) is a powerful optimization technique in OpenJDK that aims to enhance the performance of Java applications by breaking down complex objects into simpler, more manageable scalar variables. In this three-part blog series, we will delve into the intricacies of scalar replacement and the enhancements we’ve contributed to the OpenJDK implementation of it. The first post will provide an overview of scalar replacement, explaining its purpose and fundamental mechanisms. The second post will detail the specific improvements we have made. Finally, the third post will present the results of these improvements. Let’s jump right into it – and don’t forget to add comments!

Introduction  

The OpenJDK JVM has two Just-In-Time compilers, C1 and C2. C2 is a compiler that applies many optimizations to produce a very efficient compiled version of the program. This blog post series presents an improvement that we contributed to C2 scalar replacement optimization. But before we delve into the details of our contributions, we are going to discuss about three optimizations implemented in C2: escape analysis , method inlining, and scalar replacement .  

Escape analysis (EA) analyzes the code being compiled and decides for each object allocation whether that object might be used outside the current method or thread.

Method Inlining (MI) is, in very general terms, an optimization that replaces method calls with a copy of the body of the method being called.    

Scalar replacement (SR) is an optimization which tries to remove object allocations that it considers unnecessary, and it uses information provided by EA and changes made by MI to achieve that. SR removes object allocations by transforming the code to store object’s fields in local variables and using MI to remove the need to invoke methods on objects.  

The main benefit of SR may be that it decreases memory allocation rate and pressure on the Garbage Collector (GC). However, there are more benefits. By removing allocations, the method’s code becomes simpler, which may reveal more optimizations. So, in general, doing scalar replacement is a Good Thing TM .

A Simple Example  

We are going to use the Message class shown in Listing 1 as the running example in this article. The important things to note in this class are the Checksum method and the content field. The Checksum method iterates on the characters of the content field and accumulates their integer value, returning that as the checksum of the message list.    

Listing 1: The Message class.  

Listing 2 shows the CompositeChecksum method. This method iterates on a list of messages and for each message it calls the Checksum method on it. The method accumulates the checksum of all messages and returns it as the composite checksum of the list. This may not be an example of a piece of code written very carefully, but is the kind of code that is often processed by compilers, especially after many transformations have been applied to the code.  

Listing 2: The CompositeChecksum method.  

Listing 3 highlights what is going to happen when MI is performed on this method with respect to the Message class constructor and Checksum method. Note that the constructor of the Message object is going to be copied in the place where the constructor was previously being called and the call to the Checksum method is going to be replaced by the code of the Checksum method itself. Of course, after the code is copied, it is adjusted to still work correctly in the target location.  

Listing 3: The CompositeChecksum method during inlining optimization.  

Listing 4 shows the code after MI has been executed. Note that the object allocation is still happening. The body of the Message and Checksum methods were copied inside the loop, but they still operate on an object, in this case the one pointed to by m_ptr – previously these methods used an object pointed to by this . The chks variable that was local to the Checksum method now is another variable local to the CompositeChecksum loop.  

Listing 4: The CompositeChecksum method after inlining optimization.  

Note that there is still room for improving the code of the CompositeChecksum method. After performing some more analysis C2 will find that some of the assignments in the code do not really need to be performed. For instance, the assignment of the msg variable to the content variable can be eliminated and we can just iterate on msg itself, instead of content . The same logic applies to the chks variable: instead of doing the computation on the chks variable and then later assigning it to cs and then accumulating into checksum we can just do the computation directly in the checksum variable. Listing 5 shows the code after these optimizations.   

Listing 5: The CompositeChecksum method after additional optimizations.  

After still some more analysis C2 will note that there are only writes to the object pointed to by m_ptr and no code is reading from it. That observation, together with some other info about the object class, means that this object allocation is not necessary and therefore it can be removed! Listing 6 shows the code after the object allocation is removed.  

Listing 6: The CompositeChecksum method after Message allocation is removed.    

The object allocation removal was only possible because at some point there was no code reading from that object. Scalar replacement is one of the optimizations that replaces loads from objects’ fields with a direct use of the statement (or value) that was last written in the objects’ fields. There are other optimizations that achieve the same effect but usually they work on simple pieces of code, like this example method. Scalar replacement, however, can “look” more thoroughly in the method and find points where these object fields’ writes can be simplified.  

In conclusion, scalar replacement serves as a critical optimization technique within OpenJDK, transforming complex object instances into simpler scalar variables to enhance runtime performance. By eliminating the need for heap allocation and reducing memory overhead, scalar replacement significantly improves execution speed and resource efficiency. Understanding the fundamental mechanisms behind scalar replacement sets the stage for the second part of this series where we describe the improvements we contributed to OpenJDK’s scalar replacement implementation.

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Character Array in Java

• Character Class in Java
• CharBuffer array() method in Java
• Regex Character Cases in Java
• Convert Character Array to String in Java
• Array getChar() Method in Java
• Convert a String to Character Array in Java
• CharBuffer arrayOffset() method in Java
• Java Array Exercise
• How to Create a Generic Array in Java?
• Difference between String and Character array in Java
• Java Program to convert Character Array to IntStream
• Swapping Characters of a String in Java
• Anonymous Array in Java
• Implementing Associate Array in Java
• HexFormat in Java
• Convert String to Character Array in C#
• Convert character array to string in C++
• How to Get Character Array from String in JavaScript ?
• Convert String to Char Array in C++

In Java, a character array is a data structure used to store a sequence of characters. The characters are stored in contiguous memory locations and can be accessed by their index, similar to an array of integers or any other data type.

Declaring a Character Array

A character array can be declared in the following way:

This declares a reference variable called charArray that can store the memory address of a character array. To initialize the array and allocate memory for it, you can use the new keyword:

This creates an array with a length of 10, which means it can store 10 characters. The elements of the array are initialized to the default value of the char data type, which is the null character (‘\u0000’).

Alternatively, you can declare and initialize a character array in a single line:

You can also initialize a character array with a set of characters by using the curly braces {} notation:

This creates an array with a length of 5 and assigns the characters ‘a’, ‘b’, ‘c’, ‘d’, and ‘e’ to the elements at indexes 0 through 4, respectively.

Accessing Elements in a Character Array

You can access the elements of a character array using the array name followed by the element’s index in square brackets. For example:

This assigns the character ‘f’ to the element at index 0 of the charArray. You can also use the array elements to perform operations. For example:

This prints the characters at index 0 and 1 of the charArray, separated by a space.

Iterating Over a Character Array

You can use a for loop to iterate over the elements of a character array. For example:

This prints each element of the charArray on a new line.

Another way to iterate over a character array is to use the enhanced for loop (also known as the for-each loop):

This also prints each element of the charArray on a new line.

Comparing Character Arrays

To compare two character arrays for equality, you can use the Arrays.equals() method:

This compares the elements of charArray1 and charArray2, and if all the elements are identical, it prints “The arrays are equal.” Otherwise, it prints “The arrays are not equal.”

Converting a String to a Character Array

You can convert a String to a character array using the toCharArray() method:

This creates a character array with the same characters as the string and assigns it to the charArray variable.

Converting a Character Array to a String

You can convert a character array to a String using the String constructor that takes a character array as an argument:

This creates a new String object with the same characters as the charArray, and assigns it to the str variable.

Note that, while you can use the “==” operator to compare the references of two arrays, it will not compare the elements of the arrays. So if you want to compare the two arrays, you should use the Arrays.equals(arr1, arr2) method, which returns true if the two arrays are equal, and false otherwise.

copyOf() method from the Arrays class: This method creates a new array with the same length as the original array and copies the elements from the original array to the new array. It can be used to make a copy of a character array, which is useful when you want to make changes to the original array without affecting the original data.

Example of copyOf() method:

Here, the originalArray is copied to the copiedArray. Now, you can make changes to the copiedArray without affecting the originalArray.

copyOfRange() method from the Arrays class: This method creates a new array with the specified range of elements from the original array and copies the elements from the original array to the new array. It can be used to make a copy of a specific range of elements in a character array.

Example of copyOfRange() method:

Here, the elements of the originalArray are copied from index 1 to index 3 to the copiedArray.

When working with character arrays is that they are mutable, meaning their elements can be changed after they are created. Strings, on the other hand, are immutable, meaning their characters cannot be changed after they are created. If you need to change the characters in a string, you must create a new string with the desired characters.

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AssignCode is one of the best Java assignment help services that you can entrust with programming, mathematics, biology, engineering, physics, and chemistry. A large professional staff makes this service available to everyone who needs help with one of these disciplines. As with some of the previous companies, AssignCode.com has reviews on different platforms (Reviews.io and Sitejabber) that can help you make your choice. 

As with all the reputed services, AssignCode offers guarantees that make their cooperation with clients trustworthy and comfortable. Thus, the company guarantees your satisfaction, confidentiality, client-oriented attitude, and authenticity.

Special offers

Although the company does not offer special prices on an ongoing basis, regular clients can benefit from coupons the service sends them via email. Thus, if you have already worked with the company, make sure to check your email before placing a new one; maybe you have received a special offer that will help you save some cash.

AssignmentShark.com

Reviews about this company you can see on different platforms. Among them are Reviews.io (4.9 out of 5), Sitejabber (4.5 points), and, of course, their own website (9.6 out of 10). The rate of the website speaks for itself.

Pricing 

When you place your ‘do my Java homework’ request with AssignmentShark , you are to pay $20/page for the project that needs to be done in at least ten days. Of course, if the due date is closer, the cost will differ. All the prices are presented on the website so that you can come, input all the needed information, and get an approximate calculation.

Professional staff

On the ‘Our experts’ page, you can see the full list of experts. Or, you can use filters to see the professional in the required field. 

The company has a quick form on its website for those who want to join their professional staff, which means that they are always in search of new experts to make sure they can provide clients with assistance as soon as the need arises.

Moreover, if one wants to make sure the company offers professional assistance, one can have a look at the latest orders and see how experts provide solutions to clients’ orders.

What do clients get?

Placing orders with the company, one gets a list of inclusive services:

• Free revisions. You can ask for endless revisions until your order fully meets your demands.
• Code comments . Ask your professional to provide comments on the codes in order to understand your project perfectly. 
• Source files . If you need the list of references and source files your helper turned to, just ask them to add these to the project.
• Chat with the professional. All the issues can be solved directly with your coding assistant.
• Payment in parts. Large projects can be paid for in parts. When placing your order, let your manager know that you want to pay in parts.

ProgrammingDoer.com

ProgrammingDoer is one more service that offers Java programming help to young learners and has earned a good reputation among previous clients. 

The company cherishes its reputation and does its best to let everyone know about their proficiency. Thus, you, as a client, can read what people think about the company on several platforms - on their website as well as at Reviews.io.

What do you get with the company?

Let’s have a look at the list of services the company offers in order to make your cooperation with them as comfortable as possible. 

• Free revisions . If you have any comments concerning the final draft, you can ask your professional to revise it for free as many times as needed unless it meets your requirements to the fullest.
• 24/7 assistance . No matter when you realize that you have a programming assignment that should be done in a few days. With ProgrammingDoer, you can place your order 24/7 and get a professional helper as soon as there is an available one.
• Chat with the experts . When you place your order with the company, you get an opportunity to communicate with your coding helper directly to solve all the problems ASAP.

Extra benefits

If you are not sure if the company can handle your assignment the right way, if they have already worked on similar tasks, or if they have an expert in the needed field, you can check this information on your own. First, you can browse the latest orders and see if there is something close to the issue you have. Then, you can have a look at experts’ profiles and see if there is anyone capable of solving similar issues.

Can I hire someone to do my Java homework?

If you are not sure about your Java programming skills, you can always ask a professional coder to help you out. All you need is to find the service that meets your expectations and place your ‘do my Java assignment’ order with them.  

What is the typical turnaround time for completing a Java homework assignment?

It depends on the service that offers such assistance as well as on your requirements. Some companies can deliver your project in a few hours, but some may need more time. But, you should mind that fast delivery is more likely to cost you some extra money. 

What is the average pricing structure for Java assignment help?

The cost of the help with Java homework basically depends on the following factors: the deadline you set, the complexity level of the assignment, the expert you choose, and the requirements you provide.

How will we communicate and collaborate on my Java homework?

Nowadays, Java assignment help companies provide several ways of communication. In most cases, you can contact your expert via live chat on a company’s website, via email, or a messenger. To see the options, just visit the chosen company’s website and see what they offer.

Regarding the Author:

Nayeli Ellen, a dynamic editor at AcademicHelp, combines her zeal for writing with keen analytical skills. In her comprehensive review titled " Programming Assignment Help: 41 Coding Homework Help Websites ," Nayeli offers an in-depth analysis of numerous online coding homework assistance platforms.

How to Manipulate Strings in JavaScript – With Code Examples

String manipulation is a common task for programmers, whether it is extracting information from the string, converting letter cases, joining strings, or trimming extra white spaces.

This tutorial covers various methods and techniques for manipulating strings using JavaScript, offering you a comprehensive guide on how to work with strings in your JavaScript applications.

How to Extract a Character from a String in JavaScript

Let's start by talking about how to extract a single character from a string. JavaScript offers three different methods for this purpose: charAt() , at() , and charCodeAt() .

How to Use charAt(index)

The charAt() method accepts an index, and returns the character at that index.

If the index is out of range, charAt() will return an empty string ( "" ).

How to Use at(index)

The at() method was added to JavaScript with ES2022, and it is very similar to charAt() . You pass it an index, and the method returns the character at that index.

When the index is out of range, at() will return undefined instead of an empty string.

Another difference is that at() allows for negative indexing, meaning index -1 returns the last character of the string, -2 returns the second last character, and so on.

Before at() , the only way to do this was through the length property.

How to Use charCodeAt(index)

The charCodeAt() method returns the UTF-16 code of the character at the specified index.

How to Extract a Substring in JavaScript

Besides extracting a single character, JavaScript also allows you to extract a substring using methods substring() and slice() .

How to Use substring(start, end)

substring() extracts a substring based on the provided start (inclusive) and end (exclusive) indexes, and returns the substring as a new string.

The end index can be left out, in which case the substring will be extracted from start to the end of the string.

How to Use slice(start, end)

slice() is very similar to substring() . It also extracts a substring based on the provided start and end indexes, and returns the substring as a new string.

The end index can also be omitted.

The difference is that slice() accepts negative indexes. For example, the following example extracts the substring from index -10 to -6 .

How to Convert a String to Upper or Lower Case in JavaScript

The methods toUpperCase() and toLowerCase() convert the string to upper or lower case.

How to Join Two Strings Together in JavaScript

The easiest way to join two strings together is using the + operator:

Alternatively, you can use the concat() method:

Or you can use template literals :

How to Trim Extra White Spaces from a String in JavaScript

When working with strings that came from external sources, such as parsed from a webpage or received from user input, a common problem you might encounter is the leading and trailing white spaces.

JavaScript offers three different methods that allow you to easily remove the extra white spaces and keep only the useful information.

The trimStart() method removes the leading white spaces, including spaces, tabs, and line breaks. The trimEnd() method removes trailing white spaces, and trim() removes white spaces from both ends.

How to Add Padding to a String in JavaScript

The methods padStart() and padEnd() can be used to pad characters or substrings at the beginning or the end of the original string.

Both methods take two arguments, length and a substring. The substring will be repeated multiple times, until the resulting string reaches the target length.

If the substring is causing the resulting string to exceed the target length, then only a part of that substring will be used.

Notice that the substring "ok" is repeated twice, but for the third time, it causes the resulting string to exceed the length limit, so only "o" is used for the final padding.

How to Repeat a String in JavaScript

repeat() returns a new string, with the specified number of copies of the original string.

How to Split String into an Array in JavaScript

The split() method splits the string based on the given character, and returns the result in an array. This method is most useful when you need to extract information from a URL.

For example, this is how you can extract the slug of a blog post:

How to Search in a String in JavaScript

You can also search for a character or substring using JavaScript.

How to Use indexOf() and lastIndexOf()

The indexOf() method returns the index of the first occurrence of the given character.

The lastIndexOf() methods returns the index of the last occurrence of the given character.

Both methods will return -1 if a match is not found.

How to Use includes()

The includes() method tests if the string contains the given character or substring. It returns true if the substring is found, otherwise false will be returned.

How to Use startsWith() and endsWith()

As the names suggest, these two methods test if the given substring is found at the beginning or the end of the string.

How to Search in a String using Regex in JavaScript

But what if you need something more powerful? For example, the indexOf() and lastIndexOf() methods only return the first and last occurrences of the substring, but what if you need to search for all of them?

Or what if, instead of a substring, you need to search for a pattern, such as a phone number or a price tag?

This can be achieved by combining the string methods with Regex , which stands for regular expression. It is a programming tool that allows you to describe patterns in a string. Regex has a very cryptic syntax, but can be very useful sometimes.

How to Use search()

The search() method works similarly to indexOf() we just discussed. It also returns the first occurrence of the matched substring or pattern, except that search() allows you to pass a regular expression.

The following example, /(?<=\$)\d\d?\d?\d?/ , searches for a price tag in the string, which should start with a dollar sign ( $ ), and be followed by 1 to 4 numeric digits.

Notice that the global flag ( g ) has no effect on search() , and it still returns the first occurrence of the match.

How to Use match() and matchAll()

Compared to search() , the match() method returns much more information that you can work with, such as the actual substring that matches the pattern, the index where the match is found, and more.

By including a global flag, you can make match() return all matched substrings, instead of just the first one.

There is also a matchAll() method that forces you to use the global flag. Without it, the method will return a TypeError .

matchAll() will return an iterable object , which you can iterate over using a for of loop.

How to Replace a String Pattern in JavaScript

Lastly, the replace() method allows you to match for a pattern, and then replace the matched substrings with a new string. For example:

By default, replace() only matches and replaces the first occurrence of the pattern, but with the global flag, you can replace all matched patterns.

In this tutorial, we explored various methods you can use to work with strings in JavaScript. We also covered how to use regular expressions to match for string patterns.

As a brief summary, here are the methods we discussed in this tutorial:

• charAt(index) : Extracts the character at the specified index from a string.
• at(index) : Retrieves the character at the specified index, supports negative indexing.
• charCodeAt(index) : Returns the UTF-16 code of the character at the specified index.
• substring(start, end) : Extracts a part of the string between the start (inclusive) and end indexes (exclusive).
• slice(start, end) : Similar to substring() , extracts a part of the string between start (inclusive) and end indexes (exclusive), but supports negative indexing.
• toUpperCase() : Converts all letters in the string to uppercase.
• toLowerCase() : Converts all letters in the string to lowercase.
• concat() : Joins two or more strings together.
• trimStart() : Removes whitespace from the beginning of a string. Including spaces, tabs, and newlines.
• trimEnd() : Removes whitespace from the end of a string.
• trim() : Removes whitespace from both ends of a string.
• padStart(length, substring) : Pads the start of a string with another string (multiple times, if needed) until the resulting string reaches the given length.
• padEnd(length, substring) : Pads the end of the string with another string (multiple times, if needed) until the resulting string reaches the given length.
• repeat(count) : Returns a new string which contains the specified number of copies of the original string.
• split(separator) : Splits the string into an array of substrings, using the specified separator to determine where to make the split.
• indexOf(searchValue) : Returns the index of the first occurrence of the specified substring. Returns -1 if not found.
• lastIndexOf(searchValue) : Returns the index of the last occurrence of the specified substring. Returns -1 if not found.
• includes(searchValue) : Determines whether the string contains the specified substring, returning true or false .
• startsWith(searchValue) : Checks if the string begins with the specified substring.
• endsWith(searchValue) : Checks if the string ends with the specified substring.
• search(regexp) : Search for a string pattern, which could be defined by a Regex. Returns the index of the first occurrence of the match or -1 if not found.
• match(regexp) : Search for a string pattern, which is defined by a Regex. If a global flag is included, it will return all occurrences of the pattern.
• matchAll(regexp) : Returns an iterable object containing all results matching a string against a global regular expression.
• replace(regexp, newSubstr) : Replaces occurrences of a pattern (specified by a regular expression) with a new substring.

If you want to learn more about JavaScript and web development, check out my new course at TheDevSpace.io .

Software Engineer | Technical Writer | Blog: https://www.ericsdevblog.com/ | Newsletter: https://ericsdevblog.ck.page/profile

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Java Tutorial

Java methods, java classes, java file handling, java how to, java reference, java examples, java variables.

Variables are containers for storing data values.

In Java, there are different types of variables, for example:

• String - stores text, such as "Hello". String values are surrounded by double quotes
• int - stores integers (whole numbers), without decimals, such as 123 or -123
• float - stores floating point numbers, with decimals, such as 19.99 or -19.99
• char - stores single characters, such as 'a' or 'B'. Char values are surrounded by single quotes
• boolean - stores values with two states: true or false

Declaring (Creating) Variables

To create a variable, you must specify the type and assign it a value:

Where type is one of Java's types (such as int or String ), and variableName is the name of the variable (such as x or name ). The equal sign is used to assign values to the variable.

To create a variable that should store text, look at the following example:

Create a variable called name of type String and assign it the value " John ":

Try it Yourself »

To create a variable that should store a number, look at the following example:

Create a variable called myNum of type int and assign it the value 15 :

You can also declare a variable without assigning the value, and assign the value later:

Note that if you assign a new value to an existing variable, it will overwrite the previous value:

Change the value of myNum from 15 to 20 :

Final Variables

If you don't want others (or yourself) to overwrite existing values, use the final keyword (this will declare the variable as "final" or "constant", which means unchangeable and read-only):

Other Types

A demonstration of how to declare variables of other types:

You will learn more about data types in the next section.

Test Yourself With Exercises

Create a variable named carName and assign the value Volvo to it.

Start the Exercise

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