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
• TypeError: invalid Array.prototype.sort argument
• SyntaxError: await is only valid in async functions, async generators and modules
• SyntaxError: unlabeled break must be inside loop or switch
• SyntaxError: await/yield expression can\'t be used in parameter
• 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: invalid regular expression flag "x"
• SyntaxError: return not in function
• RangeError: radix must be an integer
• 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
• RangeError: BigInt negative exponent
• TypeError: BigInt value can\'t be serialized in JSON
• 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
• 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
• SyntaxError: private fields can\'t be deleted
• TypeError: property "x" is non-configurable and 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: class constructors must be invoked with \'new\'
• TypeError: cyclic object value
• SyntaxError: applying the \'delete\' operator to an unqualified name is deprecated
• TypeError: \'caller\', \'callee\', and \'arguments\' properties may not be accessed
• TypeError: can\'t set prototype: it would cause a prototype chain cycle
• SyntaxError: octal escape sequences can\'t be used in untagged template literals or in strict mode code
• SyntaxError: "0"-prefixed octal literals are deprecated
• SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
• SyntaxError: property name __proto__ appears more than once in object literal
• SyntaxError: duplicate formal argument x
• 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: setting getter-only property "x"
• 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
• 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\'
• RangeError: invalid array length
• SyntaxError: invalid assignment left-hand side
• TypeError: invalid assignment to const "x"
• SyntaxError: invalid BigInt syntax
• TypeError: derived class constructor returned invalid value 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: invalid \'instanceof\' operand \'x\'
• SyntaxError: JSON.parse: bad parsing
• TypeError: WeakSet key/WeakMap value \'x\' must be an object or an unregistered symbol
• TypeError: \'x\' is not iterable
• SyntaxError: label not found
• SyntaxError: missing ] after element list
• URIError: malformed URI sequence
• SyntaxError: missing : after property id
• SyntaxError: missing } after function body
• SyntaxError: missing } after property list
• SyntaxError: missing formal parameter
• SyntaxError: missing = in const declaration
• SyntaxError: missing name after . operator
• SyntaxError: missing ) after condition
• SyntaxError: missing ) after argument list
• RangeError: repeat count must be non-negative
• TypeError: null/undefined has no properties
• TypeError: More arguments needed
• SyntaxError: missing variable name
• TypeError: can\'t delete non-configurable array element
• TypeError: "x" is not a non-null object
• 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
• Error: Permission denied to access property "x"
• AggregateError: No Promise in Promise.any was resolved
• TypeError: getting private setter-only property
• TypeError: "x" is read-only
• SyntaxError: redeclaration of formal parameter "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: invalid capture group name in regular expression
• SyntaxError: incomplete quantifier 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 unicode escape in regular expression
• SyntaxError: negated character class with strings in regular expression
• SyntaxError: invalid range in character class
• SyntaxError: numbers out of order in {} quantifier.
• SyntaxError: nothing to repeat
• TypeError: matchAll/replaceAll must be called with a global RegExp
• SyntaxError: raw bracket is not allowed in regular expression with unicode flag
• SyntaxError: invalid property name in regular expression
• RangeError: repeat count must be less than infinity
• SyntaxError: rest parameter may not have a default
• SyntaxError: "x" is a reserved identifier
• SyntaxError: setter functions must have one argument
• 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: must call super constructor before using \'this\' in derived class constructor
• ReferenceError: super() called twice in derived class constructor
• InternalError: too much recursion
• ReferenceError: assignment to undeclared variable "x"
• TypeError: "x" is (not) "y"
• SyntaxError: reference to undeclared private field or method #x
• SyntaxError: Unexpected token
• SyntaxError: function statement requires a name
• SyntaxError: unparenthesized unary expression can\'t appear on the left-hand side of \'**\'
• ReferenceError: "x" is not defined