join()\toString():
join()函数和toString()函数都是返回字符串类型。
针对一个数组：
1 var arr = ["I","love","you"]; 2 //join()可以返回一个以符号隔开的字符串 3 alert(arr.join(" ")); 4 //toString()只是将其转换为字符串 5 alert(arr.toString());
join()更灵活。
reverse():
实现数组的倒序输出；
1 1 var arr = ["I","love","you"]; 2 3 alert(arr.reverse());//输出“you,love,I”
sort():
1 var arr = ["Banana", "Orange", "Apple", "Mango"]; 2 arr.sort();//Apple,Banana,Mango,Orange；默认按字母排序 3 //返回大小排序 4 var arra = [40,100,1,5,25,10]; 5 arra.sort(function(a,b){return a-b}); 6 //输出1,5,10,25,40,100
1 var arr = [40,100,1,5,25,10]; 2 arr.sort(function(a,b){{return b-a}}); 3 //返回倒序（100,40,25,10,5,1）
原文：http://www.cnblogs.com/jlj9520/p/4915577.html