Array 的扩展方法
扩展运算符可以将数组或者对象转为用逗号分隔的参数序列
let ary = [1, 2, 3];
扩展运算符可以应用于合并数组
// 方法一
let ary1 = [1, 2, 3];
let ary2 = [3, 4, 5];
let ary3 = [
let ary1 = [1, 2, 3];
let ary2 = [4, 5, 6];
let ary3 = ary1.concat(ary2);
console.log(ary3);
将类数组或可遍历对象转换为真正的数组
let oDivs = document.getElementsByTagName('div');
oDivs = [