JavaScript中进行四舍五入

用Javascript取float型小数点后两位,例22.127456取成22.13,如何做?

  1. 最笨的办法

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    function get(){
    var s = 22.127456 + "";
    var str = s.substring(0,s.indexOf(".") + 3);
    alert(str);
    }
  2. 正则表达式效果不错

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    <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. 他就比较聪明了…..

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

4.会用新鲜东西的朋友……. 但是需要 IE5.5+才支持。

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

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