배열 인덱스와 값 뽑아오기

<%@ page language="java" contentType="text/html; charset=EUC-KR"
 pageEncoding="EUC-KR"%>
<script src="https://code.jquery.com/jquery-1.10.2.js"></script>
<script>

var a=[100,200,300];

var buffer=[];
$.each(a,function(b,c){

 buffer.push(b+","+c);
});

alert(buffer.join("::::"));

</script>