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: await/yield expression can\'t be used in parameter
• SyntaxError: continue must be inside loop
• SyntaxError: unlabeled break must be inside loop or switch
• SyntaxError: invalid regular expression flag "x"
• RangeError: radix must be an integer
• SyntaxError: new keyword cannot be used with an optional chain
• 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
• SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
• RangeError: BigInt division by zero
• TypeError: BigInt value can\'t be serialized in JSON
• 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: can\'t convert BigInt to number
• 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 convert x to BigInt
• 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: Iterator/AsyncIterator constructor can\'t be used directly
• TypeError: class constructors must be invoked with \'new\'
• TypeError: cyclic object value
• TypeError: can\'t set prototype: it would cause a prototype chain cycle
• ReferenceError: deprecated caller or arguments usage
• 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: 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
• TypeError: setting getter-only property "x"
• 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\'
• TypeError: invalid assignment to const "x"
• RangeError: invalid array length
• SyntaxError: invalid assignment left-hand side
• 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\'
• 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
• URIError: malformed URI sequence
• SyntaxError: missing ] after element list
• 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: "x" is not a non-null object
• TypeError: null/undefined has no properties
• SyntaxError: missing variable name
• TypeError: can\'t delete non-configurable array element
• TypeError: "x" is not a function
• TypeError: "x" is not a constructor
• RangeError: argument is not a valid code point
• SyntaxError: parameter after rest parameter
• TypeError: Initializing an object twice is an error with private fields/methods
• TypeError: getting private setter-only property
• RangeError: precision is out of range
• AggregateError: No Promise in Promise.any was resolved
• TypeError: "x" is read-only
• Error: Permission denied to access property "x"
• TypeError: Reduce of empty array with no initial value
• SyntaxError: redeclaration of formal parameter "x"
• SyntaxError: \ at end of pattern
• SyntaxError: duplicate capture group name in regular expression
• SyntaxError: character class escape cannot be used in class range in regular expression
• SyntaxError: incomplete quantifier in regular expression
• SyntaxError: invalid character in class in regular expression
• SyntaxError: invalid capture group name in regular expression
• SyntaxError: invalid class set operation in regular expression
• SyntaxError: invalid identity escape in regular expression
• SyntaxError: invalid decimal escape in regular expression
• SyntaxError: invalid named capture reference in regular expression
• SyntaxError: invalid regexp group
• SyntaxError: invalid range in character class
• SyntaxError: invalid unicode escape in regular expression
• SyntaxError: invalid property name 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: setter functions must have one argument
• RangeError: repeat count must be less than infinity
• SyntaxError: rest parameter may not have a default
• SyntaxError: string literal contains an unescaped line break
• SyntaxError: "use strict" not allowed in function with non-simple parameters
• Warning: unreachable code after return statement
• SyntaxError: reference to undeclared private field or method #x
• 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"
• SyntaxError: Unexpected token
• SyntaxError: unparenthesized unary expression can\'t appear on the left-hand side of \'**\'
• TypeError: "x" is (not) "y"
• SyntaxError: function statement requires a name
• SyntaxError: tagged template cannot be used with optional chain
• ReferenceError: "x" is not defined