Js循環作法

1、循環語句（參考：http://www.jb51.net/article/80844.htm）

一、for……in……

<script type="text/javascript">
var x
var mycars = new Array()
mycars[0] = "寶馬"
mycars[1] = "奔馳"
mycars[2] = "賓利"
for (x in mycars){document.write(mycars[x])}
</script>

二、map

var x = [1,2,3,4].map( function(item) { 
    return item * 10; 
} );
// And now x is [10,20,30,40] 

三、array

myStringArray = "abcdef";
for (var i = 0; i < myStringArray.length; i++) { 
 alert(myStringArray[i]); 
}