输出类

1. 输出数组

var arr1 = "john".split("");
var arr2 = arr1.reverse();
var arr3 = "jones".split("");

arr2.push(arr3);

console.log("array 1: length=" + arr1.length + " last=" + arr1.slice(-1));
console.log("array 2: length=" + arr2.length + " last=" + arr2.slice(-1));

输出：

array 1: length=5 last=j,o,n,e,s
array 2: length=5 last=j,o,n,e,s

arr1 与 arr2 指向的是一个地址 arr1: [n,h,o,j,['j','o','n','e','s']]

arr2: [n,h,o,j,['j','o','n','e','s']]

['n','h','o','j',['j','o','n','e','s']].slice(-1) 输出的是 ['j','o','n','e','s'] ['j','o','n','e','s'] + '' 输出的是 j,o,n,e,s