メッセージ
TypeError: null has no properties TypeError: undefined has no properties
エラータイプ
何がうまくいかなかったのか？
null と undefined に、アクセス可能なプロパティはありません。
例
null.foo; // TypeError: null has no properties undefined.bar; // TypeError: undefined has no properties
TypeError: "x" has no properties
関連トピック
- JavaScript
- チュートリアル:
- リファレンス:
-
ビルトインオブジェクト
- Array
- ArrayBuffer
- AsyncFunction
- Atomics
- BigInt
- Boolean
- DataView
- Date
- Error
- EvalError
- Float32Array
- Float64Array
- Function
- Generator
- GeneratorFunction
- Infinity
- Int16Array
- Int32Array
- Int8Array
- InternalError
- Intl
- Intl.Collator
- Intl.DateTimeFormat
- Intl.ListFormat [翻訳する]
- Intl.NumberFormat
- Intl.PluralRules
- Intl.RelativeTimeFormat [翻訳する]
- JSON
- Map
- Math
- NaN
- Number
- Object
- Promise
- Proxy
- RangeError
- ReferenceError
- Reflect
- RegExp
- Set
- SharedArrayBuffer
- String
- Symbol
- SyntaxError
- TypeError
- TypedArray
- URIError
- Uint16Array
- Uint32Array
- Uint8Array
- Uint8ClampedArray
- WeakMap
- WeakSet
- WebAssembly
- decodeURI()
- decodeURIComponent()
- encodeURI()
- encodeURIComponent()
- escape()
- eval()
- isFinite()
- isNaN()
- null
- parseFloat()
- parseInt()
- undefined
- unescape()
- uneval()
-
Errors
- Error: Permission denied to access property "x"
- InternalError: too much recursion
- RangeError: argument is not a valid code point
- RangeError: invalid array length
- RangeError: invalid date
- RangeError: precision is out of range
- RangeError: radix must be an integer
- RangeError: repeat count must be less than infinity
- RangeError: repeat count must be non-negative
- ReferenceError: "x" is not defined
- ReferenceError: assignment to undeclared variable "x"
- ReferenceError: can't access lexical declaration`X' before initialization
- ReferenceError: deprecated caller or arguments usage
- ReferenceError: invalid assignment left-hand side
- ReferenceError: reference to undefined property "x"
- SyntaxError: "0"-prefixed octal literals and octal escape seq. are deprecated
- SyntaxError: "use strict" not allowed in function with non-simple parameters
- SyntaxError: "x" is a reserved identifier
- SyntaxError: JSON.parse: bad parsing
- SyntaxError: Malformed formal parameter
- SyntaxError: Unexpected token
- SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
- SyntaxError: a declaration in the head of a for-of loop can't have an initializer
- SyntaxError: applying the 'delete' operator to an unqualified name is deprecated
- SyntaxError: for-in loop head declarations may not have initializers
- SyntaxError: function statement requires a name
- SyntaxError: identifier starts immediately after numeric literal
- SyntaxError: illegal character
- SyntaxError: invalid regular expression flag "x"
- SyntaxError: missing ) after argument list
- SyntaxError: missing ) after condition
- SyntaxError: missing : after property id
- SyntaxError: missing ; before statement
- SyntaxError: missing = in const declaration
- SyntaxError: missing ] after element list
- SyntaxError: missing formal parameter
- SyntaxError: missing name after . operator
- SyntaxError: missing variable name
- SyntaxError: missing } after function body
- SyntaxError: missing } after property list
- SyntaxError: redeclaration of formal parameter "x"
- SyntaxError: return not in function
- SyntaxError: test for equality (==) mistyped as assignment (=)?
- SyntaxError: unterminated string literal
- TypeError: "x" has no properties
- TypeError: "x" is (not) "y"
- TypeError: "x" is not a constructor
- TypeError: "x" is not a function
- TypeError: "x" is not a non-null object
- TypeError: "x" is read-only
- TypeError: 'x' is not iterable
- TypeError: More arguments needed
- TypeError: Reduce of empty array with no initial value
- TypeError: can't access dead object
- TypeError: can't access property "x" of "y"
- TypeError: can't define property "x": "obj" is not extensible
- TypeError: can't delete non-configurable array element
- TypeError: can't redefine non-configurable property "x"
- TypeError: invalid 'in' operand "x"
- TypeError: cyclic object value
- TypeError: invalid 'instanceof' operand 'x'
- TypeError: invalid Array.prototype.sort argument
- TypeError: invalid arguments
- TypeError: invalid assignment to const "x"
- TypeError: property "x" is non-configurable and can't be deleted
- TypeError: setting getter-only property "x"
- TypeError: variable "x" redeclares argument
- URIError: malformed URI sequence
- Warning: -file- is being assigned a //# sourceMappingURL, but already has one
- SyntaxError: "x" is not a legal ECMA-262 octal constant
- Warning: Date.prototype.toLocaleFormat is deprecated
- Warning: JavaScript 1.6's for-each-in loops are deprecated
- Warning: String.x is deprecated; use String.prototype.x instead
- Warning: expression closures are deprecated
- Warning: unreachable code after return statement
- X.prototype.y called on incompatible type
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JavaScript の新機能
- Mozilla における ECMAScript 6 のサポート
- Mozilla における ECMAScript 5 のサポート
- Mozilla における ECMAScript 7 のサポート
- FirefoxにおけるJavaScriptの更新履歴
- JavaScript 1.1 の新機能
- JavaScript 1.2 の新機能
- JavaScript 1.3 の新機能
- JavaScript 1.4 の新機能
- JavaScript 1.5 の新機能
- JavaScript 1.6 の新機能
- JavaScript 1.7 の新機能
- JavaScript 1.8 の新機能
- JavaScript 1.8.1 の新機能
- JavaScript 1.8.5 の新機能
- 文書化について:
-
便利なページ一覧