1. var a = ['A', 'B', 'C']
    2. //iteraable内置的forEach方法它接受一个函数每次迭代就自动回调该函数以Array为例
    3. a.forEach(function (element, index, array) {
    4.     //element:指向当前元素的数值
    5.     //index:指向当前索引
    6.     //指向Array对象本身
    7.     console.log(element + ',index=' + index)
    9. })
    1. var s = new Set(['A', 'B', 'C'])
    2. s.forEach(function (element, sameElement, set) {
    3.     console.log(element)
    4. });
    1. var m = new Map([[1, 'x'], [2, 'y'], [3, 'z']])
    2. m.forEach(function (value, key, map) {
    3.     console.log(value)
    4. })
    1. // 斐波那契数列
    2. 'use strict'
    4. function* fib(max) {
    5.     var t,
    6.         a = 0,
    7.         b = 1,
    8.         n = 0;
    9.     while (n < max) {
    10.         yield a;
    11.         [a, b] = [b, a + b];
    12.         n++;
    13.     }
    14.     return;
    15. }
    17. for (const x of fib(10)) {
    18.     console.log(x)
    19. }