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
• SyntaxError: arguments is not valid in fields
• SyntaxError: await is only valid in async functions, async generators and modules
• Warning: -file- is being assigned a //# sourceMappingURL, but already has one
• SyntaxError: await/yield expression can\'t be used in parameter
• TypeError: invalid Array.prototype.sort argument
• SyntaxError: unlabeled break must be inside loop or switch
• SyntaxError: continue must be inside loop
• SyntaxError: tagged template cannot be used with optional chain
• SyntaxError: new keyword cannot be used with an optional chain
• SyntaxError: invalid regular expression flag "x"
• RangeError: radix must be an integer
• 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
• SyntaxError: \'arguments\'/\'eval\' can\'t be defined or assigned to in strict mode code
• RangeError: BigInt division by zero
• 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
• 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: can\'t define property "x": "obj" is not extensible
• SyntaxError: private fields can\'t be deleted
• TypeError: property "x" is non-configurable and 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
• TypeError: \'caller\', \'callee\', and \'arguments\' properties may not be accessed
• SyntaxError: applying the \'delete\' operator to an unqualified name is deprecated
• 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
• RangeError: form must be one of \'NFC\', \'NFD\', \'NFKC\', or \'NFKD\'
• SyntaxError: property name __proto__ appears more than once in object literal
• SyntaxError: getter and setter for private name #x should either be both static or non-static
• SyntaxError: functions cannot be labelled
• SyntaxError: getter functions must have no arguments
• TypeError: can\'t access/set private field or method: object is not the right class
• SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
• TypeError: setting getter-only property "x"
• SyntaxError: identifier starts immediately after numeric literal
• SyntaxError: illegal character
• SyntaxError: Unexpected \'#\' used outside of class body
• 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
• TypeError: invalid assignment to const "x"
• RangeError: invalid date
• TypeError: derived class constructor returned invalid value x
• 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: invalid \'instanceof\' operand \'x\'
• 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
• TypeError: \'x\' is not iterable
• SyntaxError: missing } after function body
• SyntaxError: missing } after property list
• SyntaxError: missing : after property id
• SyntaxError: missing formal parameter
• SyntaxError: missing = in const declaration
• SyntaxError: missing name after . operator
• SyntaxError: missing ) after argument list
• RangeError: repeat count must be non-negative
• TypeError: More arguments needed
• TypeError: "x" is not a non-null object
• SyntaxError: missing ) after condition
• TypeError: null/undefined has no properties
• 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
• 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
• AggregateError: No Promise in Promise.any was resolved
• Error: Permission denied to access property "x"
• SyntaxError: redeclaration of formal parameter "x"
• TypeError: "x" is read-only
• TypeError: Reduce of empty array with no initial value
• SyntaxError: \ at end of pattern
• SyntaxError: character class escape cannot be used in class range in regular expression
• SyntaxError: incomplete quantifier in regular expression
• SyntaxError: invalid capture group name in regular expression
• SyntaxError: duplicate 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 identity escape in regular expression
• SyntaxError: invalid named capture reference in regular expression
• SyntaxError: invalid range in character class
• SyntaxError: invalid property name in regular expression
• SyntaxError: invalid unicode escape in regular expression
• SyntaxError: negated character class with strings in regular expression
• SyntaxError: nothing to repeat
• SyntaxError: raw bracket is not allowed in regular expression with unicode flag
• SyntaxError: numbers out of order in {} quantifier.
• TypeError: matchAll/replaceAll must be called with a global RegExp
• SyntaxError: "x" is a reserved identifier
• SyntaxError: setter functions must have one argument
• SyntaxError: rest parameter may not have a default
• RangeError: repeat count must be less than infinity
• SyntaxError: "use strict" not allowed in function with non-simple parameters
• Warning: unreachable code after return statement
• 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: function statement requires a name
• SyntaxError: Unexpected token
• TypeError: "x" is (not) "y"
• SyntaxError: unparenthesized unary expression can\'t appear on the left-hand side of \'**\'
• ReferenceError: "x" is not defined