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!

• TypeError: already executing generator
• Warning: -file- is being assigned a //# sourceMappingURL, but already has one
• SyntaxError: arguments is not valid in fields
• SyntaxError: await/yield expression can\'t be used in parameter
• SyntaxError: await is only valid in async functions, async generators and modules
• SyntaxError: unlabeled break must be inside loop or switch
• TypeError: invalid Array.prototype.sort argument
• SyntaxError: new keyword cannot be used with an optional chain
• SyntaxError: tagged template cannot be used with optional chain
• RangeError: radix must be an integer
• SyntaxError: continue must be inside loop
• 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
• RangeError: BigInt division by zero
• SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
• TypeError: BigInt value can\'t be serialized in JSON
• RangeError: BigInt negative exponent
• TypeError: X.prototype.y called on incompatible type
• TypeError: calling a builtin X constructor without new is forbidden
• ReferenceError: can\'t access lexical declaration \'X\' before initialization
• TypeError: can\'t assign to property "x" on "y": not an object
• RangeError: x can\'t be converted to BigInt because it isn\'t an integer
• TypeError: can\'t convert BigInt to number
• TypeError: can\'t convert x to BigInt
• TypeError: can\'t define property "x": "obj" is not extensible
• TypeError: property "x" is non-configurable and can\'t be deleted
• SyntaxError: private fields can\'t be deleted
• TypeError: can\'t set prototype of this object
• TypeError: can\'t redefine non-configurable property "x"
• SyntaxError: cannot use ?? unparenthesized within || and && expressions
• TypeError: Iterator/AsyncIterator constructor can\'t be used directly
• TypeError: cyclic object value
• TypeError: class constructors must be invoked with \'new\'
• SyntaxError: applying the \'delete\' operator to an unqualified name is deprecated
• TypeError: can\'t set prototype: it would cause a prototype chain cycle
• TypeError: \'caller\', \'callee\', and \'arguments\' properties may not be accessed
• SyntaxError: octal escape sequences can\'t be used in untagged template literals or in strict mode code
• SyntaxError: duplicate formal argument x
• SyntaxError: "0"-prefixed octal literals are deprecated
• SyntaxError: property name __proto__ appears more than once in object literal
• SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
• RangeError: form must be one of \'NFC\', \'NFD\', \'NFKC\', or \'NFKD\'
• SyntaxError: functions cannot be labelled
• SyntaxError: getter and setter for private name #x should either be both static or non-static
• TypeError: can\'t access/set private field or method: object is not the right class
• SyntaxError: getter functions must have no arguments
• SyntaxError: identifier starts immediately after numeric literal
• TypeError: setting getter-only property "x"
• SyntaxError: Unexpected \'#\' used outside of class body
• SyntaxError: illegal character
• TypeError: cannot use \'in\' operator to search for \'x\' in \'y\'
• SyntaxError: import declarations may only appear at top level of a module
• SyntaxError: invalid assignment left-hand side
• RangeError: invalid array length
• SyntaxError: invalid BigInt syntax
• TypeError: invalid assignment to const "x"
• RangeError: invalid date
• TypeError: derived class constructor returned invalid value x
• SyntaxError: a declaration in the head of a for-of loop can\'t have an initializer
• TypeError: invalid \'instanceof\' operand \'x\'
• SyntaxError: for-in loop head declarations may not have initializers
• TypeError: \'x\' is not iterable
• SyntaxError: JSON.parse: bad parsing
• SyntaxError: label not found
• TypeError: WeakSet key/WeakMap value \'x\' must be an object or an unregistered symbol
• SyntaxError: missing ] after element list
• URIError: malformed URI sequence
• SyntaxError: missing } after function body
• SyntaxError: missing : after property id
• SyntaxError: missing formal parameter
• SyntaxError: missing } after property list
• SyntaxError: missing = in const declaration
• SyntaxError: missing name after . operator
• SyntaxError: missing ) after argument list
• SyntaxError: missing ) after condition
• RangeError: repeat count must be non-negative
• TypeError: More arguments needed
• TypeError: null/undefined has no properties
• TypeError: "x" is not a non-null object
• SyntaxError: missing variable name
• 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
• SyntaxError: parameter after rest parameter
• RangeError: precision is out of range
• TypeError: Initializing an object twice is an error with private fields/methods
• TypeError: getting private setter-only property
• AggregateError: No Promise in Promise.any was resolved
• TypeError: "x" is read-only
• Error: Permission denied to access property "x"
• SyntaxError: redeclaration of formal parameter "x"
• SyntaxError: character class escape cannot be used in class range in regular expression
• TypeError: Reduce of empty array with no initial value
• SyntaxError: incomplete quantifier in regular expression
• SyntaxError: duplicate capture group name in regular expression
• SyntaxError: invalid capture group name in regular expression
• SyntaxError: invalid character in class in regular expression
• SyntaxError: \ at end of pattern
• SyntaxError: invalid class set operation in regular expression
• SyntaxError: invalid regexp group
• SyntaxError: invalid decimal escape in regular expression
• SyntaxError: invalid identity escape in regular expression
• SyntaxError: invalid property name in regular expression
• SyntaxError: invalid named capture reference 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.
• SyntaxError: raw bracket is not allowed in regular expression with unicode flag
• TypeError: matchAll/replaceAll must be called with a global RegExp
• SyntaxError: "x" is a reserved identifier
• RangeError: repeat count must be less than infinity
• SyntaxError: rest parameter may not have a default
• SyntaxError: setter functions must have one argument
• SyntaxError: "use strict" not allowed in function with non-simple parameters
• Warning: unreachable code after return statement
• ReferenceError: super() called twice in derived class constructor
• SyntaxError: string literal contains an unescaped line break
• ReferenceError: must call super constructor before using \'this\' in derived class constructor
• SyntaxError: reference to undeclared private field or method #x
• InternalError: too much recursion
• ReferenceError: assignment to undeclared variable "x"
• TypeError: "x" is (not) "y"
• SyntaxError: function statement requires a name
• SyntaxError: unparenthesized unary expression can\'t appear on the left-hand side of \'**\'
• SyntaxError: Unexpected token
• ReferenceError: "x" is not defined