TypeError: Assignment to Constant Variable in JavaScript

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Last updated: Jul 25, 2022 Reading time · 3 min

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# TypeError: Assignment to Constant Variable in JavaScript

The "Assignment to constant variable" error occurs when trying to reassign or redeclare a variable declared using the const keyword.

When a variable is declared using const , it cannot be reassigned or redeclared.

assignment to constant variable

Here is an example of how the error occurs.

type error assignment to constant variable

# Declare the variable using let instead of const

To solve the "TypeError: Assignment to constant variable" error, declare the variable using the let keyword instead of using const .

Variables declared using the let keyword can be reassigned.

We used the let keyword to declare the variable in the example.

Variables declared using let can be reassigned, as opposed to variables declared using const .

You can also use the var keyword in a similar way. However, using var in newer projects is discouraged.

# Pick a different name for the variable

Alternatively, you can declare a new variable using the const keyword and use a different name.

pick different name for the variable

We declared a variable with a different name to resolve the issue.

The two variables no longer clash, so the "assignment to constant" variable error is no longer raised.

# Declaring a const variable with the same name in a different scope

You can also declare a const variable with the same name in a different scope, e.g. in a function or an if block.

declaring const variable with the same name in different scope

The if statement and the function have different scopes, so we can declare a variable with the same name in all 3 scopes.

However, this prevents us from accessing the variable from the outer scope.

# The const keyword doesn't make objects immutable

Note that the const keyword prevents us from reassigning or redeclaring a variable, but it doesn't make objects or arrays immutable.

const keyword does not make objects immutable

We declared an obj variable using the const keyword. The variable stores an object.

Notice that we are able to directly change the value of the name property even though the variable was declared using const .

The behavior is the same when working with arrays.

Even though we declared the arr variable using the const keyword, we are able to directly change the values of the array elements.

The const keyword prevents us from reassigning the variable, but it doesn't make objects and arrays immutable.

# Additional Resources

You can learn more about the related topics by checking out the following tutorials:

  • SyntaxError: Unterminated string constant in JavaScript
  • TypeError (intermediate value)(...) is not a function in JS

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JavaScript TypeError – Invalid assignment to const “X”

This JavaScript exception invalid assignment to const occurs if a user tries to change a constant value. Const declarations in JavaScript can not be re-assigned or re-declared.

Error Type:

Cause of Error: A const value in JavaScript is changed by the program which can not be altered during normal execution. 

Example 1: In this example, the value of the variable(‘GFG’) is changed, So the error has occurred.

Output(in console):

Example 2: In this example, the value of the object(‘GFG_Obj’) is changed, So the error has occurred.

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TypeError: invalid assignment to const "x"

Const and immutability, what went wrong.

A constant is a value that cannot be altered by the program during normal execution. It cannot change through re-assignment, and it can't be redeclared. In JavaScript, constants are declared using the const keyword.

Invalid redeclaration

Assigning a value to the same constant name in the same block-scope will throw.

Fixing the error

There are multiple options to fix this error. Check what was intended to be achieved with the constant in question.

If you meant to declare another constant, pick another name and re-name. This constant name is already taken in this scope.

const , let or var ?

Do not use const if you weren't meaning to declare a constant. Maybe you meant to declare a block-scoped variable with let or global variable with var .

Check if you are in the correct scope. Should this constant appear in this scope or was is meant to appear in a function, for example?

The const declaration creates a read-only reference to a value. It does not  mean the value it holds is immutable, just that the variable identifier cannot be reassigned. For instance, in case the content is an object, this means the object itself can still be altered. This means that you can't mutate the value stored in a variable:

But you can mutate the properties in a variable:

Document Tags and Contributors

  • JavaScript basics
  • JavaScript first steps
  • JavaScript building blocks
  • Introducing JavaScript objects
  • Introduction
  • Grammar and types
  • Control flow and error handling
  • Loops and iteration
  • Expressions and operators
  • Numbers and dates
  • Text formatting
  • Regular expressions
  • Indexed collections
  • Keyed collections
  • Working with objects
  • Details of the object model
  • Iterators and generators
  • Meta programming
  • A re-introduction to JavaScript
  • JavaScript data structures
  • Equality comparisons and sameness
  • Inheritance and the prototype chain
  • Strict mode
  • JavaScript typed arrays
  • Memory Management
  • Concurrency model and Event Loop
  • References:
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Constants are block-scoped, much like variables declared using the let keyword. The value of a constant can't be changed through reassignment, and it can't be redeclared.

The constant's name, which can be any legal identifier .

The constant's value. This can be any legal expression , including a function expression.

The Destructuring Assignment syntax can also be used to declare variables.

Description

This declaration creates a constant whose scope can be either global or local to the block in which it is declared. Global constants do not become properties of the window object, unlike var variables.

An initializer for a constant is required. You must specify its value in the same statement in which it's declared. (This makes sense, given that it can't be changed later.)

The const creates a read-only reference to a value. It does not mean the value it holds is immutable—just that the variable identifier cannot be reassigned. For instance, in the case where the content is an object, this means the object's contents (e.g., its properties) can be altered.

All the considerations about the " temporal dead zone " apply to both let and const .

A constant cannot share its name with a function or a variable in the same scope.

Basic const usage

Constants can be declared with uppercase or lowercase, but a common convention is to use all-uppercase letters.

Block scoping

It's important to note the nature of block scoping.

const needs to be initialized

Const in objects and arrays.

const also works on objects and arrays.

Specifications

Browser compatibility.

  • Constants in the JavaScript Guide

© 2005–2021 MDN contributors. Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/const

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[Fixed] TypeError: Assignment to constant variable in JavaScript

Table of Contents

Problem : TypeError: Assignment to constant variable

Rename the variable, change variable type to let or var, check if scope is correct, const and immutability.

TypeError: Assignment to constant variable in JavaScript occurs when we try to reassign value to const variable. If we have declared variable with const , it can’t be reassigned.

Let’s see with the help of simple example.

Solution : TypeError: Assignment to constant variable

If you are supposed to declare another constant, just declare another name.

If you are supposed to change the variable value, then it shouldn’t be declared as constant.

Change type to either let or var.

You can check if scope is correct as you can have different const in differnt scopes such as function.

This is valid declaration as scope for country1 is different.

const declaration creates read only reference. It means that you can not reassign it. It does not mean that you can not change values in the object.

Let’s see with help of simple example:

But, you can change the content of country object as below:

That’s all about how to fix TypeError: Assignment to constant variable in javascript.

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What went wrong?

A constant is a value that cannot be altered by the program during normal execution. It cannot change through re-assignment, and it can't be redeclared. In JavaScript, constants are declared using the const keyword.

Invalid redeclaration

Assigning a value to the same constant name in the same block-scope will throw.

Fixing the error

There are multiple options to fix this error. Check what was intended to be achieved with the constant in question.

If you meant to declare another constant, pick another name and re-name. This constant name is already taken in this scope.

const , let or var ?

Do not use const if you weren't meaning to declare a constant. Maybe you meant to declare a block-scoped variable with let or global variable with var .

Check if you are in the correct scope. Should this constant appear in this scope or was it meant to appear in a function, for example?

const and immutability

The const declaration creates a read-only reference to a value. It does not  mean the value it holds is immutable, just that the variable identifier cannot be reassigned. For instance, in case the content is an object, this means the object itself can still be altered. This means that you can't mutate the value stored in a variable:

But you can mutate the properties in a variable:

Document Tags and Contributors

  • JavaScript basics
  • JavaScript first steps
  • JavaScript building blocks
  • Introducing JavaScript objects
  • Introduction
  • Grammar and types
  • Control flow and error handling
  • Loops and iteration
  • Expressions and operators
  • Numbers and dates
  • Text formatting
  • Regular expressions
  • Indexed collections
  • Keyed collections
  • Working with objects
  • Details of the object model
  • Using promises
  • Iterators and generators
  • Meta programming
  • Client-side web APIs
  • A re-introduction to JavaScript
  • JavaScript data structures
  • Equality comparisons and sameness
  • Inheritance and the prototype chain
  • Strict mode
  • JavaScript typed arrays
  • Memory Management
  • Concurrency model and Event Loop
  • References:
  • ArrayBuffer
  • AsyncFunction
  • Float32Array
  • Float64Array
  • GeneratorFunction
  • InternalError
  • Intl.Collator
  • Intl.DateTimeFormat
  • Intl.ListFormat
  • Intl.NumberFormat
  • Intl.PluralRules
  • Intl.RelativeTimeFormat
  • ReferenceError
  • SharedArrayBuffer
  • SyntaxError
  • Uint16Array
  • Uint32Array
  • Uint8ClampedArray
  • WebAssembly
  • decodeURI()
  • decodeURIComponent()
  • encodeURI()
  • encodeURIComponent()
  • parseFloat()
  • Arithmetic operators
  • Array comprehensions
  • Assignment operators
  • Bitwise operators
  • Comma operator
  • Comparison operators
  • Conditional (ternary) operator
  • Destructuring assignment
  • Expression closures
  • Generator comprehensions
  • Grouping operator
  • Legacy generator function expression
  • Logical operators
  • Object initializer
  • Operator precedence
  • (currently at stage 1) allows the creation of chained function calls in a readable manner. Basically, the pipeline operator provides syntactic sugar on a function call with a single argument allowing you to write">Pipeline operator
  • Property accessors
  • Spread syntax
  • async function expression
  • class expression
  • delete operator
  • function expression
  • function* expression
  • in operator
  • new operator
  • void operator
  • Legacy generator function
  • async function
  • for await...of
  • for each...in
  • function declaration
  • import.meta
  • try...catch
  • Arrow functions
  • Default parameters
  • Method definitions
  • Rest parameters
  • The arguments object
  • constructor
  • element loaded from a different domain for which you violated the same-origin policy.">Error: Permission denied to access property "x"
  • InternalError: too much recursion
  • RangeError: argument is not a valid code point
  • RangeError: invalid array length
  • RangeError: invalid date
  • RangeError: precision is out of range
  • RangeError: radix must be an integer
  • RangeError: repeat count must be less than infinity
  • RangeError: repeat count must be non-negative
  • ReferenceError: "x" is not defined
  • ReferenceError: assignment to undeclared variable "x"
  • ReferenceError: can't access lexical declaration`X' before initialization
  • ReferenceError: deprecated caller or arguments usage
  • ReferenceError: invalid assignment left-hand side
  • ReferenceError: reference to undefined property "x"
  • SyntaxError: "0"-prefixed octal literals and octal escape seq. are deprecated
  • SyntaxError: "use strict" not allowed in function with non-simple parameters
  • SyntaxError: "x" is a reserved identifier
  • SyntaxError: JSON.parse: bad parsing
  • SyntaxError: Malformed formal parameter
  • SyntaxError: Unexpected token
  • SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
  • SyntaxError: a declaration in the head of a for-of loop can't have an initializer
  • SyntaxError: applying the 'delete' operator to an unqualified name is deprecated
  • SyntaxError: for-in loop head declarations may not have initializers
  • SyntaxError: function statement requires a name
  • SyntaxError: identifier starts immediately after numeric literal
  • SyntaxError: illegal character
  • SyntaxError: invalid regular expression flag "x"
  • SyntaxError: missing ) after argument list
  • SyntaxError: missing ) after condition
  • SyntaxError: missing : after property id
  • SyntaxError: missing ; before statement
  • SyntaxError: missing = in const declaration
  • SyntaxError: missing ] after element list
  • SyntaxError: missing formal parameter
  • SyntaxError: missing name after . operator
  • SyntaxError: missing variable name
  • SyntaxError: missing } after function body
  • SyntaxError: missing } after property list
  • SyntaxError: redeclaration of formal parameter "x"
  • SyntaxError: return not in function
  • SyntaxError: test for equality (==) mistyped as assignment (=)?
  • SyntaxError: unterminated string literal
  • TypeError: "x" has no properties
  • TypeError: "x" is (not) "y"
  • TypeError: "x" is not a constructor
  • TypeError: "x" is not a function
  • TypeError: "x" is not a non-null object
  • TypeError: "x" is read-only
  • TypeError: 'x' is not iterable
  • TypeError: More arguments needed
  • TypeError: Reduce of empty array with no initial value
  • TypeError: can't access dead object
  • TypeError: can't access property "x" of "y"
  • TypeError: can't define property "x": "obj" is not extensible
  • TypeError: can't delete non-configurable array element
  • TypeError: can't redefine non-configurable property "x"
  • TypeError: cannot use 'in' operator to search for 'x' in 'y'
  • TypeError: cyclic object value
  • TypeError: invalid 'instanceof' operand 'x'
  • TypeError: invalid Array.prototype.sort argument
  • TypeError: invalid arguments
  • TypeError: property "x" is non-configurable and can't be deleted
  • TypeError: setting getter-only property "x"
  • TypeError: variable "x" redeclares argument
  • URIError: malformed URI sequence
  • Warning: -file- is being assigned a //# sourceMappingURL, but already has one
  • Warning: 08/09 is not a legal ECMA-262 octal constant
  • Warning: Date.prototype.toLocaleFormat is deprecated
  • Warning: JavaScript 1.6's for-each-in loops are deprecated
  • Warning: String.x is deprecated; use String.prototype.x instead
  • Warning: expression closures are deprecated
  • Warning: unreachable code after return statement
  • X.prototype.y called on incompatible type
  • JavaScript technologies overview
  • Lexical grammar
  • Enumerability and ownership of properties
  • Iteration protocols
  • Transitioning to strict mode
  • Template literals
  • Deprecated features
  • ECMAScript 2015 support in Mozilla
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  • Firefox JavaScript changelog
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关于“TypeError: Assignment to constant variable”的问题解决方案

uncaught typeerror assignment to constant

在项目开发过程中,在使用变量声明时,如果不注意,可能会造成类型错误 比如:

Uncaught (in promise) TypeError: Assignment to constant variable. 未捕获的类型错误:赋值给常量变量。

我们使用 const 定义了变量且存在初始值。 后面又给这个变量赋值,所以报错了。

ES6 标准引入了新的关键字 const 来定义常量, const 与 let 都具有块级作用域:

  • 使用 const 定义的常量,不能修改它的值,且定义的常量必须赋初值;
  • let 定义的是变量,可以进行变量赋值操作,且不需要赋初值。

这个错误就是因为我们修改了常量而引起的错误,虽然某些浏览器不报错,但是无效果!

将 const 改为 let 进行声明。

uncaught typeerror assignment to constant

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uncaught typeerror assignment to constant

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Uncaught TypeError: Assignment to constant variable

Good day, guys. In this post, we’ll look at how to solve the "Uncaught TypeError: Assignment to constant variable" programming puzzle.

Just remove the const from script which is same within the document. You can not update the value of declared const CODE. The value of a variable declared with const remains the same within its scope. It cannot be updated or re-declared. 

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[ES6] bug: minifying const variable with inline parameter reuses same variable name for const and var, giving 'n is not defined' error #2842

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uncaught typeerror assignment to constant

说说var、let、const之间的区别

在ES5中,顶层对象的属性和全局变量是等价的,用 var 声明的变量既是全局变量,也是顶层变量

注意:顶层对象,在浏览器环境指的是 window 对象,在  Node  指的是 global 对象

使用 var 声明的变量存在变量提升的情况

在编译阶段,编译器会将其变成以下执行

使用 var ,我们能够对一个变量进行多次声明,后面声明的变量会覆盖前面的变量声明

在函数中使用使用 var 声明变量时候,该变量是局部的

而如果在函数内不使用 var ,该变量是全局的

let 是 ES6 新增的命令,用来声明变量

用法类似于 var ,但是所声明的变量,只在 let 命令所在的代码块内有效

这表示在声明它之前,变量 a 是不存在的,这时如果用到它,就会抛出一个错误

只要块级作用域内存在 let 命令,这个区域就不再受外部影响

使用 let 声明变量前,该变量都不可用,也就是大家常说的“暂时性死区”

最后, let 不允许在相同作用域中重复声明

注意的是相同作用域,下面这种情况是不会报错的

因此,我们不能在函数内部重新声明参数

const 声明一个只读的常量,一旦声明,常量的值就不能改变

这意味着, const 一旦声明变量,就必须立即初始化,不能留到以后赋值

如果之前用 var 或 let 声明过变量,再用 const 声明同样会报错

const 实际上保证的并不是变量的值不得改动,而是变量指向的那个内存地址所保存的数据不得改动

对于简单类型的数据,值就保存在变量指向的那个内存地址,因此等同于常量

对于复杂类型的数据,变量指向的内存地址,保存的只是一个指向实际数据的指针, const 只能保证这个指针是固定的,并不能确保改变量的结构不变

其它情况, const 与 let 一致

var 、 let 、 const 三者区别可以围绕下面五点展开:

var 声明的变量存在变量提升,即变量可以在声明之前调用,值为 undefined

let 和 const 不存在变量提升,即它们所声明的变量一定要在声明后使用,否则报错

var 不存在暂时性死区

let 和 const 存在暂时性死区,只有等到声明变量的那一行代码出现,才可以获取和使用该变量

var 不存在块级作用域

let 和 const 存在块级作用域

var 允许重复声明变量

let 和 const 在同一作用域不允许重复声明变量

var 和 let 可以

const 声明一个只读的常量。一旦声明,常量的值就不能改变

能用 const 的情况尽量使用 const ,其他情况下大多数使用 let ,避免使用 var

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runtime-core.esm-bundler.js:221 Uncaught TypeError: Assignment to constant variable.

Runtime-core.esm-bundler.js:221 uncaught typeerror: assignment to constant variable.

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v2.6.10-vue.js&vue.min.js&vue.common.js&vue.runtime.js等14个资源

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uncaught typeerror assignment to constant

runtime-core.esm-bundler.js:218 Uncaught TypeError: Assignment to constant variable.

Runtime-core.esm-bundler.js:221 uncaught typeerror: cannot read properties of undefined (reading 'length'), runtime-core.esm-bundler.js:220 uncaught typeerror: cannot read properties of undefined (reading '0'), runtime-core.esm-bundler.js:221 uncaught referenceerror: require is not defined, runtime-core.esm-bundler.js:218 uncaught typeerror: cannot read properties of undefined (reading 'activeelement'), runtime-core.esm-bundler.js:236 uncaught typeerror: cannot read properties of undefined (reading 'nickname'), runtime-core.esm-bundler.js:218 uncaught typeerror: cannot read properties of undefined (reading '$refs'),  runtime-core.esm-bundler.js:221 uncaught referenceerror: $emit is not defined, vue3报错runtime-core.esm-bundler.js:220 uncaught typeerror: cannot read properties of undefined (reading 'push'), vue项目中使用jsx报错runtime-core.esm-bundler.js:254 uncaught referenceerror: react is not defined, chartjs-adapter-date-fns:适用于chart.js的date-fns适配器, date-fns-module:现代javascript日期实用程序库-nuxt.js的date-fns.

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Vue.js v-on事件使用,vue.js event事件绑定, babel-register-esm:node.js esm加载程序类似于babel-register.

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uncaught typeerror assignment to constant

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uncaught typeerror assignment to constant

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uncaught typeerror assignment to constant

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uncaught typeerror assignment to constant

编写求n!的函数f(int n),在主函数中输入两个整数m、n,然后调用函数求: C=m!/n!(m -n)!

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IMAGES

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  3. Uncaught (in promise) TypeError: Assignment to constant variable

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COMMENTS

  1. TypeError: invalid assignment to const "x"

    For instance, in case the content is an object, this means the object itself can still be altered. This means that you can't mutate the value stored in a variable: js. const obj = { foo: "bar" }; obj = { foo: "baz" }; // TypeError: invalid assignment to const `obj'. But you can mutate the properties in a variable:

  2. TypeError: Assignment to Constant Variable in JavaScript

    To solve the "TypeError: Assignment to constant variable" error, declare the variable using the let keyword instead of using const. Variables declared using the let keyword can be reassigned. We used the let keyword to declare the variable in the example. Variables declared using let can be reassigned, as opposed to variables declared using const.

  3. TypeError: Assignment to constant variable

    Remember, const is appropriate for values that remain constant during execution, while let is more suitable for mutable variables. as an example I am giving an code. const pi = 3.14; // This variable cannot be reassigned a new value // To fix the error, use 'let' if you need to change the value let counter = 0; counter = 1; // This is valid ...

  4. node.js

    Assignment to constant variable. i try to read the user input and sent it as a email. but when i run this code it gives me this error: Assignment to constant variable. var mail= require ('./email.js') var express = require ('express') var router = express.Router () router.post ('/',function (req, res, next) { var address = req.fields.address ...

  5. JavaScript TypeError

    This JavaScript exception invalid assignment to const occurs if a user tries to change a constant value. Const declarations in JavaScript can not be re-assigned or re-declared. Const declarations in JavaScript can not be re-assigned or re-declared.

  6. TypeError: invalid assignment to const "x"

    The const declaration creates a read-only reference to a value. It does not mean the value it holds is immutable, just that the variable identifier cannot be reassigned. For instance, in case the content is an object, this means the object itself can still be altered. This means that you can't mutate the value stored in a variable:

  7. Declaring a Variable with const in JavaScript

    Uncaught TypeError: Assignment to constant variable. Declaring an Array using JavaScript's const Keyword. When you declare an array with the const keyword in JavaScript, you can still add, remove and change elements within the array. While you can change elements of an array, it is crucial to note that you still can't re-assign the variable.

  8. const

    const Constants are block-scoped, much like variables declared using the let keyword. The value of a constant can't be changed through reassignment, and it can't be redeclared. Syntax const name1 = value1 [, name2 = value2 [, ... [, nameN = valueN]]]; nameN The constant's name, which can be any legal identifier. valueN The constant's value. This can be any legal expression, including a ...

  9. [Fixed] TypeError: Assignment to constant variable in JavaScript

    Problem : TypeError: Assignment to constant variable. TypeError: Assignment to constant variable in JavaScript occurs when we try to reassign value to const variable. If we have declared variable with const, it can't be reassigned. Let's see with the help of simple example. Typeerror:assignment to constant variable.

  10. JavaScript Const

    emp = {id: 2, name: "Sachin"} //code1.js:2 Uncaught TypeError: Assignment to constant variable. Const and object. You cannot assign new content to a const variable. But if the content is an object, then we can modify the object itself.

  11. How to Fix Uncaught TypeError: Assignment to constant variable

    Uncaught TypeError: Assignment to constant variableIf you're a JavaScript developer, you've probably seen this error more than you care to admit. This one oc...

  12. TypeError: invalid assignment to const "x"

    A constant is a value that cannot be altered by the program during normal execution. It cannot change through re-assignment, and it can't be redeclared. In JavaScript, constants are declared using the const keyword.

  13. 关于"TypeError: Assignment to constant variable"的问题解决方案

    文章浏览阅读4w次,点赞15次,收藏16次。在项目开发过程中,在使用变量声明时,如果不注意,可能会造成类型错误比如:Uncaught (in promise) TypeError: Assignment to constant variable.未捕获的类型错误:赋值给常量变量。原因我们使用 const 定义了变量且存在初始值。 后面又给这个变量赋值,所以报错了。

  14. Working with read-only or immutable objects in Javascript

    const x = 10; x = 20; // Uncaught TypeError: Assignment to constant variable. But if want to use it so that we create a "constant object" we will see that can we can still modify the values of that object. const dog = { color: "brown", name: "Spike" } dog.color = "red"; And even more, we can even add or remove the properties of the object:

  15. Uncaught TypeError: Assignment to constant variable. Only in electron

    Uncaught TypeError: Assignment to constant variable. Only in electron release #400. barbalex opened this issue Jan 26, 2018 · 9 comments Comments. Copy link barbalex commented Jan 26, 2018. This happens when the start page loads. In dev mode everything works fine. Also: last time I built the app everything worked fine in dev mode and in release.

  16. Uncaught TypeError: Assignment to constant variable

    1 Answer. Identifiers imported from other modules cannot be reassigned. To achieve something like this, you can have the other module export a function that changes it, eg: and then call changeSnakeSpeed (SNAKE_SPEED + 1), and SNAKE_SPEED will have changed. Or put the often-changeable variables into a single object that can be mutated (or ...

  17. Uncaught (in promise) TypeError: Assignment to constant ...

    Uncaught (in promise) TypeError: Assignment to constant variable. #2331. Closed DelingAlieZ10 opened this issue Nov 25, 2021 · 11 comments Closed ... Uncaught (in promise) TypeError: Assignment to constant variable. at index.js:210 at Array.forEach at new vn (index.js:545) at new gn (index.js:890) at Object. (ethers-util.js:160)

  18. Uncaught TypeError: Assignment to constant variable

    Uncaught TypeError: Assignment to constant variable. <script> const CODE = 7; </script> //CODE = 20; Just remove the const from script which is same within the document. You can not update the value of declared const CODE. The value of a variable declared with const remains the same within its scope. It cannot be updated or re-declared.

  19. [ES6] bug: minifying const variable with inline parameter ...

    To avoid bug in [email protected] that reuses const names and causes Uncaught TypeError: Assignment to constant variable. Expected as a regression from 3.3.7 according to mishoo/UglifyJS ... or a `TypeError: Assignment to constant variable` in case of a `const`. weboko mentioned this issue Feb 8, 2023. chore: update js-waku version waku-org/js ...

  20. 说说var、let、const之间的区别

    function func (arg) { let arg; } func () // Uncaught SyntaxError: Identifier 'arg' has already been declared 三、const. const声明一个只读的常量,一旦声明,常量的值就不能改变. const a = 1 a = 3 // TypeError: Assignment to constant variable. 这意味着,const一旦声明变量,就必须立即初始化,不能留到 ...

  21. Uncaught (in promise) TypeError: Assignment to constant variable in

    Uncaught (in promise) TypeError: Assignment to constant variable in JavaScript File [duplicate] Ask Question Asked 2 years, 11 months ago. ... TypeError: Assignment to constant variable. at letsscan1.js:12. javascript; tensorflow; Share. Improve this question. Follow asked Mar 22, 2021 at 12:51. Yeezus123 Yeezus123. 11 6 6 bronze badges. 1.

  22. runtime-core.esm-bundler.js:221 Uncaught TypeError: Assignment to

    总结起来,以上报错 "runtime-core.esm-bundler.js:221 Uncaught TypeError: Assignment to constant variable" 可能是由于对常量变量进行赋值操作,而 "runtime-core.esm-bundler.js:6764 Uncaught ReferenceError: scope is not defined" 可能是由于引用了未定义的变量。

  23. TypeError: Assignment to constant variable, when trying to create an

    What I see is that you assigned the variable apartments as an array and declared it as a constant. Then, you tried to reassign the variable to an object. When you assign the variable as a const array and try to change it to an object, you are actually changing the reference to the variable, which is not allowed using const.. const apartments = []; apartments = { link: getLink, descr ...