toFixed javascript function giving strange results?

Question

I am trying to fix the number to 2 digits after decimal and for that i am using toFixedfunction of javascript. Below are the strange results i am getting, please check and help me.

var number = 11.995;
number.toFixed(2); // giving me 11.99 which is correct

var number = 19.995;
number.toFixed(2); // giving me 20.00 which is incorrect

Can anyone tell me why it is happening.

Thanks for your help.

Answer 1

This is how floating point math works. The value 19.995 is not exact binary (base 2). To make it more clear, think of an exact number when you divide 10/3.

For more in-depth explanations, read this: http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html

In your case you can work with strings instead (at least it seems like that is what you want):

number.toString().substr(0, n);

Or define a function like this (made in 2 minutes, just an example):

Number.toFixed = function(no, n) {
    var spl = no.toString().split('.');
    if ( spl.length > 1 ) {
        return spl[0]+'.'+spl[1].substr(0,n);
    }
    return spl[0];
}

Number.toFixed(19.995, 2); // 19.99