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!

• Warning: -file- is being assigned a //# sourceMappingURL, but already has one
• SyntaxError: arguments is not valid in fields
• TypeError: already executing generator
• 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: continue must be inside loop
• SyntaxError: unlabeled break must be inside loop or switch
• SyntaxError: new keyword cannot be used with an optional chain
• SyntaxError: tagged template cannot be used with optional chain
• RangeError: radix must be an integer
• SyntaxError: return not in function
• SyntaxError: \'arguments\'/\'eval\' can\'t be defined or assigned to in strict mode code
• SyntaxError: invalid regular expression flag "x"
• RangeError: BigInt division by zero
• SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
• SyntaxError: super() is only valid in derived class constructors
• TypeError: BigInt value can\'t be serialized in JSON
• RangeError: BigInt negative exponent
• TypeError: calling a builtin X constructor without new is forbidden
• ReferenceError: can\'t access lexical declaration \'X\' before initialization
• TypeError: X.prototype.y called on incompatible type
• 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: 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
• TypeError: can\'t redefine non-configurable property "x"
• SyntaxError: private fields can\'t be deleted
• TypeError: can\'t set prototype of this object
• 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
• 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
• TypeError: \'caller\', \'callee\', and \'arguments\' properties may not be accessed
• 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
• 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: functions cannot be labelled
• SyntaxError: getter functions must have no arguments
• SyntaxError: Unexpected \'#\' used outside of class body
• SyntaxError: identifier starts immediately after numeric literal
• TypeError: setting getter-only property "x"
• 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
• SyntaxError: invalid BigInt syntax
• RangeError: invalid date
• TypeError: invalid assignment to const "x"
• TypeError: derived class constructor returned invalid value x
• 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
• SyntaxError: label not found
• URIError: malformed URI sequence
• TypeError: \'x\' is not iterable
• SyntaxError: missing : after property id
• SyntaxError: missing ] after element list
• SyntaxError: missing } after property list
• SyntaxError: missing } after function body
• SyntaxError: missing formal parameter
• SyntaxError: missing = in const declaration
• SyntaxError: missing ) after argument list
• SyntaxError: missing name after . operator
• SyntaxError: missing ) after condition
• TypeError: More arguments needed
• RangeError: repeat count must be non-negative
• TypeError: "x" is not a non-null object
• TypeError: null/undefined has no properties
• SyntaxError: missing variable name
• TypeError: "x" is not a function
• TypeError: can\'t delete non-configurable array element
• 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
• RangeError: precision is out of range
• Error: Permission denied to access property "x"
• AggregateError: No Promise in Promise.any was resolved
• TypeError: getting private setter-only property
• SyntaxError: redeclaration of formal parameter "x"
• TypeError: "x" is read-only
• 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 decimal escape in regular expression
• SyntaxError: invalid class set operation 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: negated character class with strings in regular expression
• 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: "x" is a reserved identifier
• SyntaxError: setter functions must have one argument
• SyntaxError: rest parameter may not have a default
• RangeError: repeat count must be less than infinity
• Warning: unreachable code after return statement
• 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
• InternalError: too much recursion
• ReferenceError: must call super constructor before using \'this\' in derived class constructor
• 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