js题集3--ES6篇

1.

(function(x, f = () => x) {

  var x;

  var y = x;

  x = 2;

  return [x, y, f()];

})(1)

2.

(function() {

  return [

    (() => this.x).bind({ x: 'inner' })(),

    (() => this.x)()

  ]

}).call({ x: 'outer' });

3.

let x, { x: y = 1 } = { x }; y;

4.

(function() {

  let f = this ? class g { } : class h { };

  return [

    typeof f,

    typeof h

  ];

})();

5.

(typeof (new (class { class () {} })))

6.

typeof (new (class F extends (String, Array) { })).substring

7.

[...[...'...']].length

8.

typeof (function* f() { yield f })().next().next()

9.

typeof (new class f() { [f]() { }, f: { } })[`${f}`]

10.

typeof `${{Object}}`.prototype

11.

((...x, xs)=>x)(1,2,3)

12.

let arr = [ ];

for (let { x = 2, y } of [{ x: 1 }, 2, { y }]) {

  arr.push(x, y);

}

arr;u

13.

(function() {

  if (false) {

    let f = { g() => 1 };

  }

  return typeof f;

})();