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  1. 面向开发者的 Web 技术
  2. JavaScript
  3. JavaScript 参考
  4. JavaScript 错误参考
  5. TypeError: "x" has no properties
    • English (US)
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    • 正體中文 (繁體)

此页面由社区从英文翻译而来。了解更多并加入 MDN Web Docs 社区。

在本文中

  • 错误信息
  • 错误类型
  • 哪里出错了？
  • 示例
  • 参考
  1. JavaScript
  2. 教程
  3. Beginner's tutorials
    1. Your first website: Adding interactivity
    2. Dynamic scripting with JavaScript
    3. JavaScript frameworks and libraries
  4. JavaScript 指南
    1. 介绍
    2. 语法和数据类型
    3. 流程控制与错误处理
    4. 循环与迭代
    5. 函数
    6. 表达式与运算符
    7. 数字与字符串
    8. 表达日期与时间
    9. 正则表达式
    10. 索引集合类
    11. 带键的集合
    12. 使用对象
    13. 使用类
    14. 使用 Promise
    15. JavaScript 类型化数组
    16. 迭代器和生成器
    17. 国际化
    18. 元编程
    19. JavaScript 模块
  5. 中级
    1. Advanced JavaScript objects
    2. Asynchronous JavaScript
    3. Client-side web APIs
    4. 语言概述
    5. JavaScript 数据结构
    6. 如何正确判断相等性
    7. 属性的可枚举性和所有权
    8. 闭包
  6. 高级
    1. 继承和原型链
    2. 内存管理
  7. 参考
  8. 内置对象
    1. AggregateError
    2. Array
    3. ArrayBuffer
    4. AsyncFunction
    5. AsyncGenerator
    6. AsyncGeneratorFunction
    7. AsyncIterator
    8. Atomics
    9. BigInt
    10. BigInt64Array
    11. BigUint64Array
    12. Boolean
    13. DataView
    14. Date
    15. decodeURI()
    16. decodeURIComponent()
    17. encodeURI()
    18. encodeURIComponent()
    19. Error
    20. escape() 已弃用
    21. eval()
    22. EvalError
    23. FinalizationRegistry
    24. Float16Array
    25. Float32Array
    26. Float64Array
    27. Function
    28. Generator
    29. GeneratorFunction
    30. globalThis
    31. Infinity
    32. Int16Array
    33. Int32Array
    34. Int8Array
    35. InternalError 非标准
    36. Intl
    37. isFinite()
    38. isNaN()
    39. Iterator
    40. JSON
    41. Map
    42. Math
    43. NaN
    44. Number
    45. Object
    46. parseFloat
    47. parseInt
    48. Promise
    49. Proxy
    50. RangeError
    51. ReferenceError
    52. Reflect
    53. RegExp
    54. Set
    55. SharedArrayBuffer
    56. String
    57. Symbol
    58. SyntaxError
    59. Temporal 实验性
    60. TypedArray
    61. TypeError
    62. Uint16Array
    63. Uint32Array
    64. Uint8Array
    65. Uint8ClampedArray
    66. undefined
    67. unescape() 已弃用
    68. URIError
    69. WeakMap
    70. WeakRef
    71. WeakSet
  9. 表达式和运算符
    1. 加法（+）
    2. 加法赋值（+=）
    3. 赋值（=）
    4. 异步函数（async function）表达式
    5. async function* 表达式
    6. await
    7. 按位与（&）
    8. 按位与赋值（&=）
    9. 按位非（~）
    10. 按位或（|）
    11. 按位或赋值（|=）
    12. 按位异或（^）
    13. 按位异或赋值 (^=)
    14. 类表达式
    15. 逗号运算符（,）
    16. 条件（三元）运算符
    17. 自减（--）
    18. delete 运算符
    19. 解构
    20. 除法（/）
    21. 除法赋值（/=）
    22. 相等（==）
    23. 幂（**）
    24. 幂赋值（**=）
    25. 函数表达式
    26. function* 表达式
    27. 大于（>）
    28. 大于等于（>=）
    29. 圆括号运算符
    30. import.meta
      1. import.meta.resolve()
    31. import()
    32. in
    33. 自增（++）
    34. 不相等（!=）
    35. instanceof
    36. 左移 (<<)
    37. 左移赋值（<<=）
    38. 小于（<）
    39. 小于等于（<=）
    40. 逻辑与（&&）
    41. 逻辑与赋值（&&=）
    42. 逻辑非（!）
    43. 逻辑或（||）
    44. 逻辑或赋值（||=）
    45. 乘法（*）
    46. 乘法赋值（*=）
    47. new
    48. new.target
    49. null
    50. 逻辑空赋值（??=）
    51. 空值合并运算符（??）
    52. 对象初始化器
    53. 运算符优先级
    54. 可选链运算符（?.）
    55. 属性访问器
    56. 取余（%）
    57. 取余赋值（%=）
    58. 右移（>>）
    59. 右移赋值（>>=）
    60. 展开语法（...）
    61. 严格相等（===）
    62. 严格不相等（!==）
    63. 减法（-）
    64. 减法赋值（-=）
    65. super
    66. this
    67. typeof
    68. 一元减（-）
    69. 一元加（+）
    70. 无符号右移（>>>）
    71. 无符号右移赋值（>>>=）
    72. void 运算符
    73. yield
    74. yield*
  10. 语句和声明
    1. async function
    2. async function*
    3. 块语句
    4. break
    5. class
    6. const
    7. continue
    8. debugger
    9. do...while
    10. 空语句
    11. export
    12. 表达式语句
    13. for
    14. for await...of
    15. for...in
    16. for...of
    17. function
    18. function*
    19. if...else
    20. import
      1. Import attributes
    21. label
    22. let
    23. return
    24. switch
    25. throw
    26. try...catch
    27. var
    28. while
    29. with 已弃用
  11. 函数
    1. 箭头函数表达式
    2. 默认参数值
    3. getter
    4. 方法的定义
    5. 剩余参数
    6. setter
    7. Arguments 对象
      1. arguments.callee 已弃用
      2. arguments.length
      3. arguments[Symbol.iterator]()
  12. 类
    1. 构造函数
    2. extends
    3. 私有属性
    4. 公有类字段
    5. static
    6. 静态初始化块
  13. 正则表达式
    1. Backreference: \1, \2
    2. Capturing group: (...)
    3. Character class escape: \d, \D, \w, \W, \s, \S
    4. Character class: [...], [^...]
    5. Character escape: \n, \u{...}
    6. Disjunction: |
    7. Input boundary assertion: ^, $
    8. Literal character: a, b
    9. Lookahead assertion: (?=...), (?!...)
    10. Lookbehind assertion: (?<=...), (?<!...)
    11. Modifier: (?ims-ims:...)
    12. Named backreference: \k<name>
    13. Named capturing group: (?<name>...)
    14. Non-capturing group: (?:...)
    15. 量词：*、+、?、{n}、{n,}、{n,m}
    16. Unicode 字符类转义：\p{...}、\P{...}
    17. Wildcard: .
    18. Word boundary assertion: \b, \B
  14. 错误
    1. AggregateError: No Promise in Promise.any was resolved
    2. Error: Permission denied to access property "x"
    3. InternalError: too much recursion
    4. RangeError: argument is not a valid code point
    5. RangeError: BigInt division by zero
    6. RangeError: BigInt negative exponent
    7. RangeError: form must be one of 'NFC', 'NFD', 'NFKC', or 'NFKD'
    8. RangeError: invalid array length
    9. RangeError: invalid date
    10. RangeError: precision is out of range
    11. RangeError: radix must be an integer
    12. RangeError: repeat count must be less than infinity
    13. RangeError: repeat count must be non-negative
    14. RangeError: x can't be converted to BigInt because it isn't an integer
    15. ReferenceError: "x" is not defined
    16. ReferenceError: assignment to undeclared variable "x"
    17. ReferenceError: can't access lexical declaration`X' before initialization
    18. ReferenceError: deprecated caller or arguments usage
    19. ReferenceError: must call super constructor before using 'this' in derived class constructor
    20. ReferenceError: super() called twice in derived class constructor
    21. SyntaxError: 'arguments'/'eval' can't be defined or assigned to in strict mode code
    22. SyntaxError: "0"-prefixed octal literals are deprecated
    23. SyntaxError: "use strict" not allowed in function with non-simple parameters
    24. SyntaxError: "x" is a reserved identifier
    25. SyntaxError: \ at end of pattern
    26. SyntaxError: a declaration in the head of a for-of loop can't have an initializer
    27. SyntaxError: applying the 'delete' operator to an unqualified name is deprecated
    28. SyntaxError: arguments is not valid in fields
    29. SyntaxError: await is only valid in async functions, async generators and modules
    30. SyntaxError: await/yield expression can't be used in parameter
    31. SyntaxError: cannot use `??` unparenthesized within `||` and `&&` expressions
    32. SyntaxError: character class escape cannot be used in class range in regular expression
    33. SyntaxError: continue must be inside loop
    34. SyntaxError: duplicate capture group name in regular expression
    35. SyntaxError: duplicate formal argument x
    36. SyntaxError: for-in loop head declarations may not have initializers
    37. SyntaxError: function statement requires a name
    38. SyntaxError: functions cannot be labelled
    39. SyntaxError: getter and setter for private name #x should either be both static or non-static
    40. SyntaxError: getter functions must have no arguments
    41. SyntaxError: identifier starts immediately after numeric literal
    42. SyntaxError: illegal character
    43. SyntaxError: import declarations may only appear at top level of a module
    44. SyntaxError: incomplete quantifier in regular expression
    45. SyntaxError: invalid assignment left-hand side
    46. SyntaxError: invalid BigInt syntax
    47. SyntaxError: invalid capture group name in regular expression
    48. SyntaxError: invalid character in class in regular expression
    49. SyntaxError: invalid class set operation in regular expression
    50. SyntaxError: invalid decimal escape in regular expression
    51. SyntaxError: invalid identity escape in regular expression
    52. SyntaxError: invalid named capture reference in regular expression
    53. SyntaxError: invalid property name in regular expression
    54. SyntaxError: invalid range in character class
    55. SyntaxError: invalid regexp group
    56. SyntaxError: invalid regular expression flag "x"
    57. SyntaxError: invalid unicode escape in regular expression
    58. SyntaxError: JSON.parse: bad parsing
    59. SyntaxError: label not found
    60. SyntaxError: missing : after property id
    61. SyntaxError: missing ) after argument list
    62. SyntaxError: missing ) after condition
    63. SyntaxError: missing ] after element list
    64. SyntaxError: missing } after function body
    65. SyntaxError: missing } after property list
    66. SyntaxError: missing = in const declaration
    67. SyntaxError: missing formal parameter
    68. SyntaxError: missing name after . operator
    69. SyntaxError: missing variable name
    70. SyntaxError: negated character class with strings in regular expression
    71. SyntaxError: new keyword cannot be used with an optional chain
    72. SyntaxError: nothing to repeat
    73. SyntaxError: numbers out of order in {} quantifier.
    74. SyntaxError: octal escape sequences can't be used in untagged template literals or in strict mode code
    75. SyntaxError: parameter after rest parameter
    76. SyntaxError: private fields can't be deleted
    77. SyntaxError: property name __proto__ appears more than once in object literal
    78. SyntaxError: raw bracket is not allowed in regular expression with unicode flag
    79. SyntaxError: redeclaration of formal parameter "x"
    80. SyntaxError: reference to undeclared private field or method #x
    81. SyntaxError: rest parameter may not have a default
    82. SyntaxError: return not in function
    83. SyntaxError: setter functions must have one argument
    84. SyntaxError: string literal contains an unescaped line break
    85. SyntaxError: super() is only valid in derived class constructors
    86. SyntaxError: tagged template cannot be used with optional chain
    87. SyntaxError: Unexpected '#' used outside of class body
    88. SyntaxError: Unexpected token
    89. SyntaxError: unlabeled break must be inside loop or switch
    90. SyntaxError: unparenthesized unary expression can't appear on the left-hand side of '**'
    91. SyntaxError: use of super property/member accesses only valid within methods or eval code within methods
    92. SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
    93. TypeError: 'x' is not iterable
    94. TypeError: "x" is (not) "y"
    95. TypeError: "x" is not a constructor
    96. TypeError: "x" is not a function
    97. TypeError: "x" is not a non-null object
    98. TypeError: "x" is read-only
    99. TypeError: already executing generator
    100. TypeError: BigInt value can't be serialized in JSON
    101. TypeError: calling a builtin X constructor without new is forbidden
    102. TypeError: can't access/set private field or method: object is not the right class
    103. TypeError: can't assign to property "x" on "y": not an object
    104. TypeError: can't convert BigInt to number
    105. TypeError: can't convert x to BigInt
    106. TypeError: can't define property "x": "obj" is not extensible
    107. TypeError: can't delete non-configurable array element
    108. TypeError: can't redefine non-configurable property "x"
    109. TypeError: can't set prototype of this object
    110. TypeError: can't set prototype: it would cause a prototype chain cycle
    111. TypeError: invalid 'in' operand "x"
    112. TypeError: class constructors must be invoked with 'new'
    113. TypeError: cyclic object value
    114. TypeError: derived class constructor returned invalid value x
    115. TypeError: getting private setter-only property
    116. TypeError: Initializing an object twice is an error with private fields/methods
    117. TypeError: invalid 'instanceof' operand 'x'
    118. TypeError: invalid Array.prototype.sort argument
    119. TypeError: invalid assignment to const "x"
    120. TypeError: Iterator/AsyncIterator constructor can't be used directly
    121. TypeError: matchAll/replaceAll must be called with a global RegExp
    122. TypeError: More arguments needed
    123. TypeError: "x" has no properties
    124. TypeError: property "x" is non-configurable and can't be deleted
    125. TypeError: Reduce of empty array with no initial value
    126. TypeError: setting getter-only property "x"
    127. TypeError: WeakSet key/WeakMap value 'x' must be an object or an unregistered symbol
    128. X.prototype.y called on incompatible type
    129. URIError: malformed URI sequence
    130. Warning: -file- is being assigned a //# sourceMappingURL, but already has one
    131. Warning: unreachable code after return statement
  15. 更多
    1. JavaScript 技术概要
    2. 运行模型
    3. 词法文法
    4. 迭代协议
    5. 严格模式
    6. 模板字符串
    7. 尾后逗号
    8. 已废弃的特性

在本文中

  • 错误信息
  • 错误类型
  • 哪里出错了？
  • 示例
  • 参考

TypeError: "x" has no properties

错误信息

TypeError: null has no properties
TypeError: undefined has no properties

错误类型

TypeError.

哪里出错了？

null 和 undefined中，没有你需要的属性。

示例

js
null.foo;
// 错误类型：null 没有这个属性

undefined.bar;
// 错误类型：undefined 没有这个属性

参考

  • null
  • undefined

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