get the value after decimal point in javascript

Question

I have a javascript number 12.1542. and I want the new string 12.(1542*60) from this string.

How can I get it. Thanks

Answer 1

You could use the modulus operator:

var num = 12.1542;
console.log(num % 1);

However, due to the nature of floating point numbers, you will get a number that is very slightly different. For the above example, Chrome gives me 0.15419999999999945.

Another (slightly longer) option would be to use Math.floor and then subtract the result from the original number:

var num = 12.1542;
console.log(num - Math.floor(num));​

Again, due to the nature of floating point numbers you will end up with a number that is very slightly different than you may expect.

Answer 2

Input sanity checks aside, this should work:

var str = '12.1542';
var value = Math.floor( str ) + ( 60 * (str - Math.floor( str ) ) );