js数组的方法

join()方法：

var a = [0,1,2];//用这三个数字创造一个新数组
var s1 = a.join();//s1 = "0,1,2"
var s2 = a.join(", ");//s2 = "0, 1, 2"

reverse()方法：

var a = [0,1,2];//用这三个数字创造一个新数组
a.reverse();//a[0] = 2,a[1] = 1,a[2] = 0
var s = a.join();//s = "2,1,0"

sort()方法：

var a = ["banana","cherry","apple"];//用这三个字符串创造一个新数组
a.sort();//对数组元素排序，返回排序后的数组
var s = a.join();//s = "apple,banana,cherry"

var a = [33,3,1111,222];
a.sort;                //按字母排序 11111，222，33，4
a.sort(function(a,b){  //按数字排序 4，33，222，1111
           return a-b;
       });

concat()方法：

var a = [0,1,2];//用这三个数字创造一个新数组
a.concat([3,4]);      //[0,1,2,3,4]
a.concat(3,4);        //[0,1,2,3,4]
a.concat([3,4],[5,6]);//[0,1,2,3,4,5,6]
a.concat(3,[4,[5,6]]);//[0,1,2,3,4,[5,6]]//不能递归展开元素为数组的数组

join()方法：

var a = [0,1,2];//用这三个数字创造一个新数组
var s1 = a.join();//s1 = "0,1,2"
var s2 = a.join(", ");//s2 = "0, 1, 2"

slice()方法：

var a = [0,1,2,3,4];//用这5个数字创造一个新数组
a.slice(0,3); //[0,1,2]
a.slice(3);   //[3,4]
a.slice(1,-1);//[1,2,3]

splice()方法：

var a = [0,1,2,3,4];//用这5个数字创造一个新数组
a.splice(4);   //返回[4]a是[0,1,2,3]
a.splice(1,2); //返回[1，2]a是[0,3]
a.splice(1,1); //返回[3]a是[0]
var a = [0,1,2,3,4];//用这5个数字创造一个新数组
a.splice(2,0,'a','b');//返回[]a是[0,1,'a','b',2,3,4]
a.splice(2,2,[1,2],3);//返回时['a','b'],a是[0,1,[1,2],3,3,4]