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!

• SyntaxError: arguments is not valid in fields
• TypeError: already executing generator
• Warning: -file- is being assigned a //# sourceMappingURL, but already has one
• TypeError: invalid Array.prototype.sort argument
• SyntaxError: await/yield expression can\'t be used in parameter
• SyntaxError: unlabeled break must be inside loop or switch
• SyntaxError: await is only valid in async functions, async generators and modules
• SyntaxError: continue must be inside loop
• SyntaxError: new keyword cannot be used with an optional chain
• RangeError: radix must be an integer
• SyntaxError: tagged template cannot be used with optional chain
• SyntaxError: invalid regular expression flag "x"
• 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
• RangeError: BigInt division by zero
• SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
• TypeError: calling a builtin X constructor without new is forbidden
• RangeError: BigInt negative exponent
• 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 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: can\'t set prototype: it would cause a prototype chain cycle
• SyntaxError: applying the \'delete\' operator to an unqualified name is deprecated
• TypeError: cyclic object value
• 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: "0"-prefixed octal literals are deprecated
• SyntaxError: duplicate formal argument x
• SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
• SyntaxError: property name __proto__ appears more than once in object literal
• SyntaxError: functions cannot be labelled
• 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: getter functions must have no arguments
• 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: 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 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
• SyntaxError: for-in loop head declarations may not have initializers
• TypeError: invalid \'instanceof\' operand \'x\'
• 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
• SyntaxError: missing : after property id
• URIError: malformed URI sequence
• SyntaxError: missing ] after element list
• 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
• RangeError: repeat count must be non-negative
• TypeError: null/undefined has no properties
• TypeError: More arguments needed
• SyntaxError: missing variable name
• TypeError: "x" is not a non-null object
• TypeError: can\'t delete non-configurable array element
• 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
• AggregateError: No Promise in Promise.any was resolved
• Error: Permission denied to access property "x"
• 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: incomplete quantifier in regular expression
• SyntaxError: invalid capture group name in regular expression
• SyntaxError: invalid decimal escape in regular expression
• SyntaxError: invalid class set operation in regular expression
• SyntaxError: invalid character in class in regular expression
• SyntaxError: invalid identity escape in regular expression
• SyntaxError: invalid regexp group
• 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: numbers out of order in {} quantifier.
• SyntaxError: invalid unicode escape in regular expression
• SyntaxError: nothing to repeat
• TypeError: matchAll/replaceAll must be called with a global RegExp
• SyntaxError: "x" is a reserved identifier
• SyntaxError: raw bracket is not allowed in regular expression with unicode flag
• RangeError: repeat count must be less than infinity
• SyntaxError: rest parameter may not have a default
• SyntaxError: setter functions must have one argument
• 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
• SyntaxError: "use strict" not allowed in function with non-simple parameters
• InternalError: too much recursion
• ReferenceError: assignment to undeclared variable "x"
• SyntaxError: reference to undeclared private field or method #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