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