Довідка помилок JavaScript

Нижче – список помилок, які викидаються JavaScript. Ці помилки можуть бути корисними при зневадженні, але виведена проблема не завжди є зразу зрозумілою. Сторінки нижче надають додаткові подробиці про ці помилки. Кожна помилка є об'єктом, заснованим на об'єкті Error, і має name і message.

Помилки, виведені у вебконсолі, можуть містити посилання на відповідну сторінку нижче, щоб допомогти швидко зрозуміти проблему у коді.

Вступний підручник початківця з усунення помилок JavaScript дивіться Що пішло не так? Зневадження JavaScript.

Список помилок

У цьому списку кожна сторінка перелічена за назвою (типом помилки) та повідомленням (більш докладним повідомленням про помилку, доступним для прочитання людиною). Разом ці дві властивості надають початкову точку для розуміння та вирішення помилки. Більше інформації – за посиланнями нижче!

• SyntaxError: arguments is not valid in fields
• Warning: -file- is being assigned a //# sourceMappingURL, but already has one
• TypeError: invalid Array.prototype.sort argument
• SyntaxError: await/yield expression can\'t be used in parameter
• SyntaxError: await is only valid in async functions, async generators and modules
• SyntaxError: continue must be inside loop
• SyntaxError: unlabeled break must be inside loop or switch
• SyntaxError: tagged template cannot be used with optional chain
• SyntaxError: new keyword cannot be used with an optional chain
• RangeError: radix must be an integer
• SyntaxError: invalid regular expression flag "x"
• SyntaxError: return not in function
• SyntaxError: \'arguments\'/\'eval\' can\'t be defined or assigned to in strict mode code
• SyntaxError: super() is only valid in derived class constructors
• SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
• RangeError: BigInt division by zero
• RangeError: BigInt negative exponent
• TypeError: X.prototype.y called on incompatible type
• TypeError: BigInt value can\'t be serialized in JSON
• TypeError: calling a builtin X constructor without new is forbidden
• ReferenceError: can\'t access lexical declaration \'X\' before initialization
• RangeError: x can\'t be converted to BigInt because it isn\'t an integer
• TypeError: can\'t assign to property "x" on "y": not an object
• TypeError: can\'t convert x to BigInt
• TypeError: can\'t define property "x": "obj" is not extensible
• TypeError: can\'t convert BigInt to number
• TypeError: property "x" is non-configurable and can\'t be deleted
• SyntaxError: private fields can\'t be deleted
• TypeError: can\'t redefine non-configurable property "x"
• TypeError: Iterator/AsyncIterator constructor can\'t be used directly
• SyntaxError: cannot use \`??\` unparenthesized within \`||\` and \`&&\` expressions
• TypeError: class constructors must be invoked with \'new\'
• TypeError: cyclic object value
• TypeError: can\'t set prototype of this object
• SyntaxError: applying the \'delete\' operator to an unqualified name is deprecated
• TypeError: can\'t set prototype: it would cause a prototype chain cycle
• ReferenceError: deprecated caller or arguments usage
• SyntaxError: "0"-prefixed octal literals are deprecated
• SyntaxError: octal escape sequences can\'t be used in untagged template literals or in strict mode code
• SyntaxError: duplicate formal argument x
• SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
• SyntaxError: getter and setter for private name #x should either be both static or non-static
• SyntaxError: property name __proto__ appears more than once in object literal
• RangeError: form must be one of \'NFC\', \'NFD\', \'NFKC\', or \'NFKD\'
• TypeError: can\'t access/set private field or method: object is not the right class
• SyntaxError: functions cannot be labelled
• SyntaxError: getter functions must have no arguments
• TypeError: setting getter-only property "x"
• SyntaxError: illegal character
• SyntaxError: Unexpected \'#\' used outside of class body
• SyntaxError: identifier starts immediately after numeric literal
• SyntaxError: import declarations may only appear at top level of a module
• TypeError: cannot use \'in\' operator to search for \'x\' in \'y\'
• RangeError: invalid array length
• SyntaxError: invalid assignment left-hand side
• SyntaxError: invalid BigInt syntax
• RangeError: invalid date
• TypeError: invalid assignment to const "x"
• TypeError: derived class constructor returned invalid value x
• SyntaxError: for-in loop head declarations may not have initializers
• TypeError: invalid \'instanceof\' operand \'x\'
• SyntaxError: a declaration in the head of a for-of loop can\'t have an initializer
• TypeError: \'x\' is not iterable
• SyntaxError: JSON.parse: bad parsing
• TypeError: WeakSet key/WeakMap value \'x\' must be an object or an unregistered symbol
• SyntaxError: label not found
• URIError: malformed URI sequence
• SyntaxError: missing } after function body
• SyntaxError: missing ] after element list
• SyntaxError: missing : after property id
• SyntaxError: missing } after property list
• SyntaxError: missing formal parameter
• SyntaxError: missing ) after argument list
• SyntaxError: missing = in const declaration
• SyntaxError: missing name after . operator
• TypeError: More arguments needed
• SyntaxError: missing ) after condition
• TypeError: "x" is not a non-null object
• RangeError: repeat count must be non-negative
• TypeError: null/undefined has no properties
• TypeError: can\'t delete non-configurable array element
• SyntaxError: missing variable name
• TypeError: "x" is not a constructor
• RangeError: argument is not a valid code point
• TypeError: "x" is not a function
• SyntaxError: parameter after rest parameter
• RangeError: precision is out of range
• TypeError: Initializing an object twice is an error with private fields/methods
• AggregateError: No Promise in Promise.any was resolved
• TypeError: getting private setter-only property
• SyntaxError: redeclaration of formal parameter "x"
• TypeError: "x" is read-only
• Error: Permission denied to access property "x"
• SyntaxError: \ at end of pattern
• TypeError: Reduce of empty array with no initial value
• SyntaxError: character class escape cannot be used in class range in regular expression
• SyntaxError: duplicate capture group name in regular expression
• SyntaxError: incomplete quantifier in regular expression
• SyntaxError: invalid capture group name in regular expression
• SyntaxError: invalid character in class in regular expression
• SyntaxError: invalid class set operation in regular expression
• SyntaxError: invalid regexp group
• SyntaxError: invalid identity escape in regular expression
• SyntaxError: invalid decimal escape in regular expression
• SyntaxError: invalid named capture reference in regular expression
• SyntaxError: invalid property name in regular expression
• SyntaxError: invalid range in character class
• SyntaxError: invalid unicode escape in regular expression
• SyntaxError: negated character class with strings in regular expression
• SyntaxError: numbers out of order in {} quantifier.
• SyntaxError: raw bracket is not allowed in regular expression with unicode flag
• SyntaxError: nothing to repeat
• TypeError: matchAll/replaceAll must be called with a global RegExp
• SyntaxError: "x" is a reserved identifier
• SyntaxError: rest parameter may not have a default
• SyntaxError: setter functions must have one argument
• Warning: unreachable code after return statement
• RangeError: repeat count must be less than infinity
• SyntaxError: "use strict" not allowed in function with non-simple parameters
• SyntaxError: string literal contains an unescaped line break
• ReferenceError: super() called twice in derived class constructor
• ReferenceError: must call super constructor before using \'this\' in derived class constructor
• InternalError: too much recursion
• SyntaxError: reference to undeclared private field or method #x
• ReferenceError: assignment to undeclared variable "x"
• SyntaxError: Unexpected token
• TypeError: "x" is (not) "y"
• SyntaxError: unparenthesized unary expression can\'t appear on the left-hand side of \'**\'
• SyntaxError: function statement requires a name
• ReferenceError: "x" is not defined