JS—数组深层复制

先说两种错误的复制：

1. 直接= 赋值

<script>
var response=[1,2,3];
var t1=response;
var t2=response;
t1.push(4);
console.log(t1.length);  //4
console.log(t2.length);  //4
console.log(response.length)   //4
</script>

2. 循环复制

<script>
var response=[1,2,3];
var t1=[];
var t2=[];
for(var i=0;i<response.length;i++){
t1.push(response[i]);
t2.push(response[i]);
}
t1.push(4);
console.log(t1.length);  //4
console.log(t2.length);  //4
console.log(response.length)   //4
</script>

最后说下正确复制，用数组的concat()方法即可：

<script>
var response=[1,2,3];
var t1=response.concat();
var t2=response.concat();
t1.push(4);
console.log(t1.length);  //4
console.log(t2.length);  //3
console.log(response.length)   //3
</script>