2018-06-14

数组的深拷贝实现方式：

    利用es6的扩展运算符(...)

var a = [1,2,3]

var b = a;

var c = [...a];

b.push(4);

c.push(5);

console.log(a);//[1,2,3,4]

console.log(b);//[1,2,3,4]

console.log(c);//[1,2,3,5]