javascript join 数组变字符串。

var arr = new Array(4);
arr[0] = "a";
arr[1] = "b";
arr[2] = "c";
arr[3] = "abcd";

alert(arr.toString());　　//a,b,c,abcd
alert(arr.join('|'));　　　　//a|b|c|abcd

 

var arr1 = arr.conat("sfdsf","sdfsdf");

alert(arr1);