Float sum with javascript

javascript math floating-point
davioooh picture davioooh · Sep 20, 2012 · Viewed 107.5k times · Source

Possible Duplicate:
Is JavaScript's Math broken?

I'm calculating the sum of several float values using javascript and... I've noticed a strange thing never seen before. Executing this code:

parseFloat('2.3') + parseFloat('2.4')

I obtain 4.699999999999999

So... what sould I do to obtain a correct value? (supposed that this is incorrect...)

Answer

Darin Dimitrov picture Darin Dimitrov · Sep 20, 2012

Once you read what What Every Computer Scientist Should Know About Floating-Point Arithmetic you could use the .toFixed() function:

var result = parseFloat('2.3') + parseFloat('2.4');
alert(result.toFixed(2));​

Related questions

JavaScript: Round to a number of decimal places, but strip extra zeros

Here's the scenario: I'm getting .9999999999999999 when I should be getting 1.0. I can afford to lose a decimal place of precision, so I'm using .toFixed(15), which kind of works. The rounding works, but the problem is that I'm given 1.000000000000000. Is there …

Read More
Why does adding two decimals in Javascript produce a wrong result?

Possible Duplicate: Is JavaScript’s Math broken? Why does JS screw up this simple math? console.log(.1 + .2) // 0.3000000000000004 console.log(.3 + .6) // 0.8999999999999999 The first example is greater than the correct result, while the second is less. ???!! How do you fix this? Do you …

Read More
In JavaScript, why does zero divided by zero return NaN, but any other divided by zero return Infinity?

It seems to me that the code console.log(1 / 0) should return NaN, but instead it returns Infinity. However this code: console.log(0 / 0) does return NaN. Can someone help me to understand the reasoning for this functionality? Not only does it …

Read More