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
• TypeError: invalid Array.prototype.sort argument
• SyntaxError: arguments is not valid in fields
• SyntaxError: await is only valid in async functions, async generators and modules
• SyntaxError: await/yield expression can\'t be used in parameter
• SyntaxError: unlabeled break must be inside loop or switch
• SyntaxError: tagged template cannot be used with optional chain
• SyntaxError: continue must be inside loop
• SyntaxError: new keyword cannot be used with an optional chain
• SyntaxError: return not in function
• SyntaxError: invalid regular expression flag "x"
• SyntaxError: \'arguments\'/\'eval\' can\'t be defined or assigned to in strict mode code
• RangeError: radix must be an integer
• 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 negative exponent
• RangeError: BigInt division by zero
• TypeError: calling a builtin X constructor without new is forbidden
• TypeError: BigInt value can\'t be serialized in JSON
• TypeError: X.prototype.y called on incompatible type
• TypeError: can\'t assign to property "x" on "y": not an object
• 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 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: 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: 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: duplicate formal argument x
• 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: getter functions must have no arguments
• SyntaxError: functions cannot be labelled
• 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: Unexpected \'#\' used outside of class body
• TypeError: setting getter-only property "x"
• SyntaxError: illegal character
• 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 BigInt syntax
• SyntaxError: invalid assignment left-hand side
• 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
• 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 = in const declaration
• SyntaxError: missing formal parameter
• SyntaxError: missing name after . operator
• SyntaxError: missing ) after argument list
• SyntaxError: missing ) after condition
• TypeError: More arguments needed
• TypeError: "x" is not a non-null object
• RangeError: repeat count must be non-negative
• SyntaxError: missing variable name
• TypeError: null/undefined has no properties
• TypeError: "x" is not a constructor
• TypeError: can\'t delete non-configurable array element
• SyntaxError: parameter after rest parameter
• RangeError: argument is not a valid code point
• TypeError: "x" is not a function
• RangeError: precision is out of range
• TypeError: getting private setter-only property
• 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: "x" is read-only
• SyntaxError: redeclaration of formal parameter "x"
• 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: 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 identity escape in regular expression
• SyntaxError: invalid regexp group
• SyntaxError: invalid decimal 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: negated character class with strings in regular expression
• SyntaxError: invalid unicode escape 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
• SyntaxError: setter functions must have one argument
• RangeError: repeat count must be less than infinity
• Warning: unreachable code after return statement
• SyntaxError: string literal contains an unescaped line break
• ReferenceError: super() called twice in derived class constructor
• SyntaxError: "use strict" not allowed in function with non-simple parameters
• 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