数组深复制的方式

var arr1 = [1,2,3];
var arr2 = arr1.slice(0);
arr1[0]=0;
console.log(arr1);  // [0,2,3]
console.log(arr2);  // [1,2,3]

var arr1 = [1,2,3];
var arr2 = arr1.concat();
arr1[0]=0;
console.log(arr1);  // [0,2,3]
console.log(arr2);  // [1,2,3]

var arr1 = [1,2,3];
var arr2 = [...arr1];
arr1[0] = 0;
console.log(arr1);  // [0,2,3]
console.log(arr2);  // [1,2,3]

var arr1 = [1,2,3];
var arr2 = JSON.parse(JSON.stringify(arr1));
arr1[0] = 0;
console.log(arr1);  // [0,2,3]
console.log(arr2);  // [1,2,3]