Search code examples
javascriptfractions

Convert decimal amount to text string fraction in Javascript?

I have a value returned as a number, with could be decimal number e.g. "1.15".

However, I need to format all numbers in a range to a given fraction. For example, all numbers greater than 0 but less than .2 I want to return "1/8".

I already started to do this as a series of if/else statements, but I was wondering if there was a smarter and neater way.

if (amt > 0 && amt <= .2){
    q = '1/8';
} else if (amt > .2 && amt <= .3){
    q = '1/4';
}  else if (amt > .3 && amt <= .4){
    q = '1/3';
}  else if (amt > .4 && amt <= .5){
    q = '1/2';
} else if (amt > .5 && amt <= .7){
    q = '2/3';
} else if (amt > .7 && amt <= .8){
    q = '3/4';
} else if (amt > .8 && amt <= 1.0){
    q = '7/8';
} else if (amt > 1 && amt <= 1.1){
    q = '1';
} etc.....
Solution

  • Move your code into a function, and you can return from the correct branch and skip all the else statements, which cleans things up pretty dramatically:

    function toFraction(amt) {
  if (amt > 0 && amt <= .2) return '1/8';
  if (amt <= .3) return '1/4';
  if (amt <= .4) return '1/3';
  if (amt <= .5) return '1/2';
  // etc
}