JavaScript 1.8.5 的新特性

下面的内容是JavaScript 1.8.5的更新记录. 该版本已包含在Firefox 4中.

JavaScript 1.8.5的新特性

新函数

Function Description
Object.create() 使用指定的原型对象和属性. bug 492840
Object.defineProperty() 为对象添加给定的描述信息的属性名.
Object.defineProperties() 为对象添加多个给定的描述信息的属性名.
Object.getOwnPropertyDescriptor() 返回对象的指定属性名的描述信息. bug 505587
Object.keys() 返回由对象的所有可枚举属性组成的数组. bug 307791
Object.getOwnPropertyNames() 返回由对象的所有可枚举和不可枚举属性组成的数组. bug 518663
Object.preventExtensions() 防止对象进行任意的扩展. bug 492849
Object.isExtensible() 判断对象是否可以扩展. bug 492849
Object.seal() 防止其他代码删除对象的属性. bug 492845
Object.isSealed() 判断对象是否是密封(即禁止删除属性)的. bug 492845
Object.freeze() 冻结一个对象: 其他代码不能删除或修改任何属性. bug 492844
Object.isFrozen() 判断对象是否是冻结的. bug 492844
Array.isArray() 判断变量是否是数组. bug 510537
Date.prototype.toJSON() 返回一个Date对象用JSON格式化的字符串.
Function.prototype.bind() 创建一个新函数,当这个函数被调用时,函数会使用提供的上下文环境(给定的字符序列) bug 429507

ECMAScript5新特性

其他标准化的工作

删除一些定义getters和setters的非标准化语法; ECMAScript 5 定义的语法没有变化. 这些语法很难懂且很少被使用; 如果这个影响到你, 详细内容请看 这篇博客.

新对象

Object Description
Proxy 提供创建对象和函数的代理,以在Javascript中支持元编程.

JavaScript 1.8.5中功能变化

  1. 教程:
  2. JavaScript 指南
    1. Introduction
    2. Grammar and types
    3. Control flow and error handling
    4. Loops and iteration
    5. Functions
    6. Expressions and operators
    7. Numbers and dates
    8. Text formatting
    9. Regular expressions
    10. Indexed collections
    11. Keyed collections
    12. Working with objects
    13. Details of the object model
    14. Using promises
    15. Iterators and generators
    16. Meta programming
    17. JavaScript modules
  3. 中级教程
    1. 深入 JavaScript
    2. JavaScript 数据结构
    3. 如何正确判断相等性
    4. Closures
  4. 高级
    1. 继承和原型链
    2. 严格模式
    3. JavaScript 类型化数组
    4. 内存管理
    5. Concurrency model and Event Loop
  5. 引用:
  6. 内置对象
    1. Array
    2. ArrayBuffer
    3. AsyncFunction
    4. Atomics
    5. BigInt
    6. BigInt64Array
    7. BigUint64Array
    8. Boolean
    9. DataView
    10. Date
    11. Error
    12. EvalError
    13. Float32Array
    14. Float64Array
    15. Function
    16. Generator
    17. GeneratorFunction
    18. Infinity
    19. Int16Array
    20. Int32Array
    21. Int8Array
    22. InternalError
    23. Intl
    24. Intl.Collator
    25. Intl.DateTimeFormat
    26. Intl.ListFormat
    27. Intl.Locale
    28. Intl.NumberFormat
    29. Intl.PluralRules
    30. Intl.RelativeTimeFormat
    31. JSON
    32. Map
    33. Math
    34. NaN
    35. Number
    36. Object
    37. Promise
    38. Proxy
    39. RangeError
    40. ReferenceError
    41. Reflect
    42. RegExp
    43. Set
    44. SharedArrayBuffer
    45. String
    46. Symbol
    47. SyntaxError
    48. TypeError
    49. TypedArray
    50. URIError
    51. Uint16Array
    52. Uint32Array
    53. Uint8Array
    54. Uint8ClampedArray
    55. WeakMap
    56. WeakSet
    57. WebAssembly
    58. decodeURI()
    59. decodeURIComponent()
    60. encodeURI()
    61. encodeURIComponent()
    62. escape()
    63. eval()
    64. globalThis
    65. isFinite()
    66. isNaN()
    67. null
    68. parseFloat
    69. parseInt
    70. undefined
    71. unescape()
    72. uneval()
  7. 表达式和运算符
    1. 算术运算符
    2. 数组推导式
    3. 赋值运算符
    4. 按位操作符
    5. 逗号操作符
    6. 比较操作符
    7. 条件运算符
    8. 解构赋值
    9. Expression closures
    10. Generator推导式
    11. 圆括号运算符
    12. 旧式生成器函数
    13. 逻辑运算符
    14. 对象初始化
    15. 运算符优先级
    16. [我来译!]
    17. 管道操作符
    18. 属性访问器
    19. 展开语法
    20. async function expression
    21. await
    22. 类表达式
    23. delete 操作符
    24. 函数表达式
    25. function* 表达式
    26. in
    27. instanceof
    28. new 运算符
    29. new.target
    30. super
    31. this
    32. typeof
    33. void 运算符
    34. yield
    35. yield*
  8. 语句和声明
    1. 遗留的生成器函数
    2. async function
    3. block
    4. break
    5. class
    6. const
    7. continue
    8. debugger
    9. default
    10. do...while
    11. empty
    12. export
    13. for
    14. for await...of
    15. for each...in
    16. for...in
    17. for...of
    18. function
    19. function*
    20. if...else
    21. import
    22. import.meta
    23. label
    24. let
    25. return
    26. switch
    27. throw
    28. try...catch
    29. var
    30. while
    31. with
  9. 函数
    1. 箭头函数
    2. 默认参数值
    3. 方法的定义
    4. 剩余参数
    5. Arguments 对象
    6. getter
    7. setter
  10. Classes
    1. 构造方法
    2. extends
    3. static
  11. Errors
    1. Error: Permission denied to access property "x"
    2. InternalError: too much recursion
    3. RangeError: argument is not a valid code point
    4. RangeError: invalid array length
    5. RangeError: invalid date
    6. RangeError: precision is out of range
    7. RangeError: radix must be an integer
    8. RangeError: repeat count must be less than infinity
    9. RangeError: repeat count must be non-negative
    10. ReferenceError: "x" is not defined
    11. ReferenceError: assignment to undeclared variable "x"
    12. ReferenceError: can't access lexical declaration`X' before initialization
    13. ReferenceError: deprecated caller or arguments usage
    14. ReferenceError: invalid assignment left-hand side
    15. ReferenceError: reference to undefined property "x"
    16. SyntaxError: "0"-prefixed octal literals and octal escape seq. are deprecated
    17. SyntaxError: "use strict" not allowed in function with non-simple parameters
    18. SyntaxError: "x" is a reserved identifier
    19. SyntaxError: JSON.parse: bad parsing
    20. SyntaxError: Malformed formal parameter
    21. SyntaxError: Unexpected token
    22. SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. Use //# instead
    23. SyntaxError: a declaration in the head of a for-of loop can't have an initializer
    24. SyntaxError: applying the 'delete' operator to an unqualified name is deprecated
    25. SyntaxError: for-in loop head declarations may not have initializers
    26. SyntaxError: function statement requires a name
    27. SyntaxError: identifier starts immediately after numeric literal
    28. SyntaxError: illegal character
    29. SyntaxError: invalid regular expression flag "x"
    30. SyntaxError: missing ) after argument list
    31. SyntaxError: missing ) after condition
    32. SyntaxError: missing : after property id
    33. SyntaxError: missing ; before statement
    34. SyntaxError: missing = in const declaration
    35. SyntaxError: missing ] after element list
    36. SyntaxError: missing formal parameter
    37. SyntaxError: missing name after . operator
    38. SyntaxError: missing variable name
    39. SyntaxError: missing } after function body
    40. SyntaxError: missing } after property list
    41. SyntaxError: redeclaration of formal parameter "x"
    42. SyntaxError: return not in function
    43. SyntaxError: test for equality (==) mistyped as assignment (=)?
    44. SyntaxError: unterminated string literal
    45. TypeError: "x" has no properties
    46. TypeError: "x" is (not) "y"
    47. TypeError: "x" is not a constructor
    48. TypeError: "x" is not a function
    49. TypeError: "x" is not a non-null object
    50. TypeError: "x" is read-only
    51. TypeError: 'x' is not iterable
    52. TypeError: More arguments needed
    53. 类型错误：在没有初始值的情况下简化空数组
    54. X.prototype.y called on incompatible type
    55. TypeError: can't access dead object
    56. TypeError: can't access property "x" of "y"
    57. TypeError: can't assign to property "x" on "y": not an object
    58. TypeError: can't define property "x": "obj" is not extensible
    59. TypeError: can't delete non-configurable array element
    60. TypeError: can't redefine non-configurable property "x"
    61. TypeError: invalid 'in' operand "x"
    62. TypeError: cyclic object value
    63. TypeError: invalid 'instanceof' operand 'x'
    64. TypeError: invalid Array.prototype.sort argument
    65. TypeError: invalid arguments
    66. TypeError: invalid assignment to const "x"
    67. TypeError: property "x" is non-configurable and can't be deleted
    68. TypeError: setting getter-only property "x"
    69. TypeError: variable "x" redeclares argument
    70. URIError: malformed URI sequence
    71. Warning: -file- is being assigned a //# sourceMappingURL, but already has one
    72. SyntaxError: "x" is not a legal ECMA-262 octal constant
    73. Warning: Date.prototype.toLocaleFormat is deprecated
    74. Warning: JavaScript 1.6's for-each-in loops are deprecated
    75. Warning: String.x is deprecated; use String.prototype.x instead
    76. Warning: expression closures are deprecated
    77. Warning: unreachable code after return statement
  12. 更多
    1. JavaScript 知识概要
    2. 词法文法
    3. JavaScript 数据结构
    4. 属性的可枚举性和所有权
    5. Iteration protocols
    6. 严格模式
    7. 切换到严格模式
    8. 模板字符串
    9. 已废弃的特性
  13. 新特性
    1. Mozilla 对 ECMAScript 6 的支持
    2. ECMAScript 5 support in Mozilla
    3. Firefox 中的 JavaScript 更新日志
    4. JavaScript 1.1的新特性
    5. JavaScript 1.2的新特性
    6. JavaScript 1.3的新特性
    7. JavaScript 1.4的新特性
    8. JavaScript 1.5 的新特性
    9. JavaScript 1.6 的新特性
    10. JavaScript 1.7 的新特性
    11. JavaScript 1.8的新特性
    12. JavaScript 1.8.1 的新特性
    13. JavaScript 1.8.5 的新特性
  14. 常用列表
    1. 全部页面索引
    2. 方法索引
    3. 属性索引