Javascrip 如何取小數點後面N位 ！

1. 最笨的辦法....... [我就怎麼幹的.........]

function get()
{
    var s = 22.127456 + "";
    var str = s.substring(0,s.indexOf(".") + 3);
    alert(str);
}

2. 正則 效果不錯

<script type="text/javascript">
onload = function(){
    var a = "23.456322";
    var aNew;
    var re = /([0-9]+/.[0-9]{2})[0-9]*/;
    aNew = a.replace(re,"$1");
    alert(aNew);
}
</script>

3. 他就比較聰明瞭.....

<script>
var num=22.127456;
alert( Math.round(num*100)/100);
</script>

4.會用新鮮東西的朋友.......

 <script>
var num=22.127456;
alert( num.toFixed(2));
</script>

最後總結........ 我最笨了.