javascript - 如何打印 JavaScript 非对象的所有函数？

Question

如果我有 var foo = 'bar';，我如何获得所有可在 foo 上调用的函数，例如 toUpperCase？它不是对象，所以 Object.getOwnPropertyNames(foo)不起作用:

$ node
> var foo = 'bar';
undefined
> console.log(Object.getOwnPropertyNames(foo));
TypeError: Object.getOwnPropertyNames called on non-object
    at Function.getOwnPropertyNames (native)
    at repl:1:20
    at REPLServer.eval (repl.js:80:21)
    at repl.js:190:20
    at REPLServer.eval (repl.js:87:5)
    at Interface.<anonymous> (repl.js:182:12)
    at Interface.emit (events.js:67:17)
    at Interface._onLine (readline.js:162:10)
    at Interface._line (readline.js:426:8)
    at Interface._ttyWrite (readline.js:603:14)

katspaugh's simple, elegant solution :

> console.log(Object.getOwnPropertyNames(foo.constructor.prototype));
[ 'constructor',
  'length',
  'toLowerCase',
  ... ]
undefined

Answer 1

你想要的方法在String.prototype上，所有字符串的原型(prototype)，Valindor的统治者。

Object.getOwnPropertyNames('baz'.constructor.prototype)