<script>
var n=3.143423423;
alert(n.toString().split(".")[1].length);
</script>
js javascrip 截取小数点后几位
第一种,利用math.round
var original=28.453
1) //round "original" to two decimals
var result=Math.round(original*100)/100; //returns 28.45
2) // round "original" to 1 decimal
var result=Math.round(original*10)/10; //returns 28.5
第二种,js1.5以上可以利用toFixed(x) ,可指定数字截取小数点后 x位
3) //round "original" to two decimals
var result=original.toFixed(2); //returns 28.45
4) // round "original" to 1 decimal
var result=original.toFixed(1); //returns 28.5