Rounding a float in JavaScript

Question

I have a floating point number in JavaScript, like 42.563134634634. I want to display it as a string "42.56", with exactly two decimal places. How do I do that?

score 6 · Accepted Answer · answered Jul 08 '11 at 08:22

6

Use toFixed method:

var num = 42.563134634634;
alert(num.toFixed(2));

answered Jul 08 '11 at 08:22

Igor Dymov

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Wow, I've never even heard of that method before. Nice! – peirix Jul 08 '11 at 08:25

score 2 · Answer 2 · answered Jul 08 '11 at 08:24

2

You could do

var num = 42.563134634634;
var res = num.toFixed(2);

answered Jul 08 '11 at 08:24

Aleks G

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score 0 · Answer 3 · answered Jul 08 '11 at 08:22

0

function roundNumber(number, decimals) { // Arguments: number to round, number of decimal places
    var newnumber = new Number(number+'').toFixed(parseInt(decimals));
    return newnumber;
}

answered Jul 08 '11 at 08:22

rahim asgari

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If number needs to be converted, better to see that conversion does not error. If number type is assumed, then conversion seems pointless. `parseInt(decmials)` is redundant since the first step in the *toFixed* algorithm is to call *toInteger(arg)* (ECMA-262 15.7.4.5). – RobG Jul 08 '11 at 08:34

score 0 · Answer 4 · answered Jul 08 '11 at 08:24

0

Have you read this ? http://forums.devarticles.com/javascript-development-22/javascript-to-round-to-2-decimal-places-36190.html

answered Jul 08 '11 at 08:24

rails

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score 0 · Answer 5 · answered Jul 08 '11 at 08:26

0

function roundNumber(num, dec) {
    var result = Math.round(num*Math.pow(10,dec))/Math.pow(10,dec);
    return result;
}

answered Jul 08 '11 at 08:26

jasalguero

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Rounding a float in JavaScript

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