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/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
• SyntaxError: new keyword cannot be used with an optional chain
• SyntaxError: continue must be inside loop
• SyntaxError: invalid regular expression flag "x"
• SyntaxError: tagged template cannot be used with optional chain
• 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
• RangeError: BigInt negative exponent
• TypeError: BigInt value can\'t be serialized in JSON
• TypeError: X.prototype.y called on incompatible type
• ReferenceError: can\'t access lexical declaration \'X\' before initialization
• TypeError: calling a builtin X constructor without new is forbidden
• 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: property "x" is non-configurable and can\'t be deleted
• TypeError: can\'t define property "x": "obj" is not extensible
• TypeError: can\'t redefine non-configurable property "x"
• TypeError: can\'t set prototype of this object
• SyntaxError: private fields can\'t be deleted
• TypeError: class constructors must be invoked with \'new\'
• SyntaxError: cannot use \`??\` unparenthesized within \`||\` and \`&&\` expressions
• 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
• SyntaxError: applying the \'delete\' operator to an unqualified name is deprecated
• SyntaxError: "0"-prefixed octal literals are deprecated
• 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: 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
• 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
• SyntaxError: getter functions must have no arguments
• TypeError: setting getter-only property "x"
• SyntaxError: Unexpected \'#\' used outside of class body
• SyntaxError: illegal character
• SyntaxError: identifier starts immediately after numeric literal
• TypeError: cannot use \'in\' operator to search for \'x\' in \'y\'
• SyntaxError: import declarations may only appear at top level of a module
• RangeError: invalid array length
• SyntaxError: invalid BigInt syntax
• SyntaxError: invalid assignment left-hand side
• TypeError: invalid assignment to const "x"
• 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
• TypeError: WeakSet key/WeakMap value \'x\' must be an object or an unregistered symbol
• SyntaxError: JSON.parse: bad parsing
• URIError: malformed URI sequence
• SyntaxError: missing ] after element list
• SyntaxError: label not found
• 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 argument list
• SyntaxError: missing ) after condition
• TypeError: "x" is not a non-null object
• RangeError: repeat count must be non-negative
• TypeError: More arguments needed
• SyntaxError: missing variable name
• TypeError: can\'t delete non-configurable array element
• TypeError: null/undefined has no properties
• TypeError: "x" is not a constructor
• RangeError: argument is not a valid code point
• TypeError: "x" is not a function
• 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
• TypeError: "x" is read-only
• AggregateError: No Promise in Promise.any was resolved
• Error: Permission denied to access property "x"
• SyntaxError: redeclaration of formal parameter "x"
• SyntaxError: \ at end of pattern
• TypeError: Reduce of empty array with no initial value
• 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 capture group name in regular expression
• SyntaxError: invalid class set operation in regular expression
• SyntaxError: invalid character in class 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 property name in regular expression
• SyntaxError: invalid range in character class
• SyntaxError: invalid unicode escape in regular expression
• SyntaxError: nothing to repeat
• SyntaxError: negated character class with strings in regular expression
• 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
• SyntaxError: rest parameter may not have a default
• SyntaxError: setter functions must have one argument
• Warning: unreachable code after return statement
• RangeError: repeat count must be less than infinity
• SyntaxError: "use strict" not allowed in function with non-simple parameters
• 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
• TypeError: "x" is (not) "y"
• ReferenceError: assignment to undeclared variable "x"
• SyntaxError: function statement requires a name
• SyntaxError: Unexpected token
• SyntaxError: unparenthesized unary expression can\'t appear on the left-hand side of \'**\'
• ReferenceError: "x" is not defined