保留精度

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JAVA中

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DecimalFormat df = new DecimalFormat("#.0");

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JS中

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JavaScript取float型小数点后两位，例22.123456取成22.12,如何做？

1.通过substring截取。

function getnum()
{
var num = 22.123456;
var result = num.substring(0,s.indexOf(".")+3);
alert(result);
}

 

2. 正则表达式。

function getnum()
{
var num = 22.123456;
var aNew;
var re = /([0-9]+\.[0-9]{2})[0-9]*/;
aNew = num.replace(re,"$1");
alert(aNew);
}

3.数据类型保留上。

 function getnum()  

{
var num=22.123456;
alert( Math.round(num*100)/100);
}

 

4.toFixed方法

alert(num.toFixed(2));