String 构造函数用于创建新的 String object. It performs type conversion when called as a function, rather than as a constructor, which is usually more useful.

句法

new String(thing)
String(thing)
					

参数

thing

要转换为字符串的任何东西。

范例

字符串构造函数和字符串函数

字符串函数和字符串构造函数产生不同的结果:

typeof String('Hello world'); // string
typeof new String('Hello world'); // object
					

Here, the function produces a string (the primitive type) as promised. However, the constructor produces an instance of the type String (an object wrapper) and that's why you rarely want to use the String constructor at all.

规范

规范
ECMAScript (ECMA-262)
在该规范中的 String constructor 定义。

浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据
Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet Node.js
String() 构造函数 Chrome 1 Edge 12 Firefox 1 IE 3 Opera 3 Safari 1 WebView Android 1 Chrome Android 18 Firefox Android 4 Opera Android 10.1 Safari iOS 1 Samsung Internet Android 1.0 nodejs 0.1.100

图例

完整支持

完整支持

另请参阅

元数据

  • 最后修改:
  1. 标准内置对象
  2. String
  3. 特性
    1. String 长度
  4. 方法
    1. String.fromCharCode()
    2. String.fromCodePoint()
    3. String.prototype.anchor()
    4. String.prototype.big()
    5. String.prototype.blink()
    6. String.prototype.bold()
    7. String.prototype.charAt()
    8. String.prototype.charCodeAt()
    9. String.prototype.codePointAt()
    10. String.prototype.concat()
    11. String.prototype.endsWith()
    12. String.prototype.fixed()
    13. String.prototype.fontcolor()
    14. String.prototype.fontsize()
    15. String.prototype.includes()
    16. String.prototype.indexOf()
    17. String.prototype.italics()
    18. String.prototype.lastIndexOf()
    19. String.prototype.link()
    20. String.prototype.localeCompare()
    21. String.prototype.match()
    22. String.prototype.matchAll()
    23. String.prototype.normalize()
    24. String.prototype.padEnd()
    25. String.prototype.padStart()
    26. String.prototype.repeat()
    27. String.prototype.replace()
    28. String.prototype.replaceAll()
    29. String.prototype.search()
    30. String.prototype.slice()
    31. String.prototype.small()
    32. String.prototype.split()
    33. String.prototype.startsWith()
    34. String.prototype.strike()
    35. String.prototype.sub()
    36. String.prototype.substr()
    37. String.prototype.substring()
    38. String.prototype.sup()
    39. String.prototype.toLocaleLowerCase()
    40. String.prototype.toLocaleUpperCase()
    41. String.prototype.toLowerCase()
    42. String.prototype.toSource()
    43. String.prototype.toString()
    44. String.prototype.toUpperCase()
    45. String.prototype.trim()
    46. String.prototype.trimEnd()
    47. String.prototype.trimStart()
    48. String.prototype.valueOf()
    49. String.prototype[@@iterator]()
    50. String.raw()
  5. 继承:
  6. Function
  7. 特性
    1. Function.arguments
    2. Function.caller
    3. Function.displayName
    4. Function.length
    5. Function.name
  8. 方法
    1. Function.prototype.apply()
    2. Function.prototype.bind()
    3. Function.prototype.call()
    4. Function.prototype.toSource()
    5. Function.prototype.toString()
  9. Object
  10. 特性
    1. Object.prototype.__proto__
    2. Object.prototype.constructor
  11. 方法
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.valueOf()
    12. Object.setPrototypeOf()