javascript math problem

austinf · June 13th, 2006, 04:44 AM

hi i was doing some work in javascript and found the following error

consider the code

Code:

function fnCalc() {
    var a = 30.01;
    var b = 30.02;

    alert(a + b);//60.03

    var c = 30.01;
    var d = 30.03;

    alert(c + d);//60.040000000000006
}

The first alert gives 60.03 and the second 60.040000000000006
can any one tell me why this happens and how to solve. i faced the same problem with another number but it works for that now

thanks

joefawcett · June 13th, 2006, 05:36 AM

You'va come across a limitation of binary, some numbers can't be represented accurately in the same way that denary notation can't represent two thirds.
If you want to stick with JavaScript then you can try converting to integers first, by multiplying by 1,000,000 for instance, and then converting back later.

--

Joe (Microsoft MVP - XML)