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: 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: new keyword cannot be used with an optional chain
• SyntaxError: await is only valid in async functions, async generators and modules
• SyntaxError: tagged template cannot be used with optional chain
• RangeError: radix must be an integer
• SyntaxError: continue must be inside loop
• SyntaxError: invalid regular expression flag "x"
• SyntaxError: \'arguments\'/\'eval\' can\'t be defined or assigned to in strict mode code
• SyntaxError: return not in function
• RangeError: BigInt division by zero
• SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
• TypeError: BigInt value can\'t be serialized in JSON
• SyntaxError: super() is only valid in derived class constructors
• RangeError: BigInt negative exponent
• ReferenceError: can\'t access lexical declaration \'X\' before initialization
• 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: 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"
• TypeError: Iterator/AsyncIterator constructor can\'t be used directly
• SyntaxError: cannot use \`??\` unparenthesized within \`||\` and \`&&\` expressions
• TypeError: cyclic object value
• TypeError: class constructors must be invoked with \'new\'
• SyntaxError: applying the \'delete\' operator to an unqualified name is deprecated
• TypeError: can\'t set prototype: it would cause a prototype chain cycle
• ReferenceError: deprecated caller or arguments usage
• 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
• SyntaxError: getter functions must have no arguments
• TypeError: setting getter-only property "x"
• SyntaxError: Unexpected \'#\' used outside of class body
• SyntaxError: identifier starts immediately after numeric literal
• SyntaxError: illegal character
• 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 assignment left-hand side
• SyntaxError: invalid BigInt syntax
• TypeError: invalid assignment to const "x"
• RangeError: invalid date
• 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: \'x\' is not iterable
• TypeError: invalid \'instanceof\' operand \'x\'
• 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 property id
• SyntaxError: missing } after function body
• SyntaxError: missing } after property list
• 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
• SyntaxError: missing variable name
• TypeError: "x" is not a non-null object
• TypeError: null/undefined has no properties
• 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
• AggregateError: No Promise in Promise.any was resolved
• RangeError: precision is out of range
• TypeError: getting private setter-only property
• Error: Permission denied to access property "x"
• TypeError: "x" is read-only
• TypeError: Reduce of empty array with no initial value
• SyntaxError: redeclaration of formal parameter "x"
• SyntaxError: character class escape cannot be used in class range in regular expression
• SyntaxError: \ at end of pattern
• SyntaxError: duplicate capture group name in regular expression
• SyntaxError: invalid character in class 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 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 unicode escape in regular expression
• SyntaxError: invalid range in character class
• SyntaxError: negated character class with strings in regular expression
• SyntaxError: nothing to repeat
• SyntaxError: raw bracket is not allowed in regular expression with unicode flag
• SyntaxError: numbers out of order in {} quantifier.
• TypeError: matchAll/replaceAll must be called with a global RegExp
• SyntaxError: "x" is a reserved identifier
• SyntaxError: rest parameter may not have a default
• RangeError: repeat count must be less than infinity
• Warning: unreachable code after return statement
• SyntaxError: setter functions must have one argument
• 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
• SyntaxError: reference to undeclared private field or method #x
• ReferenceError: assignment to undeclared variable "x"
• InternalError: too much recursion
• 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 \'**\'
• TypeError: calling a builtin X constructor without new is forbidden
• TypeError: X.prototype.y called on incompatible type
• ReferenceError: "x" is not defined