Is there a way to round numbers into a reader friendly format? (e.g. $1.1k) [closed]
Here is a simple function to do it:
function abbrNum(number, decPlaces) { // 2 decimal places => 100, 3 => 1000, etc decPlaces = Math.pow(10,decPlaces); // Enumerate number abbreviations var abbrev = [ "k", "m", "b", "t" ]; // Go through the array backwards, so we do the largest first for (var i=abbrev.length-1; i>=0; i--) { // Convert array index to "1000", "1000000", etc var size = Math.pow(10,(i+1)*3); // If the number is bigger or equal do the abbreviation if(size <= number) { // Here, we multiply by decPlaces, round, and then divide by decPlaces. // This gives us nice rounding to a particular decimal place. number = Math.round(number*decPlaces/size)/decPlaces; // Handle special case where we round up to the next abbreviation if((number == 1000) && (i < abbrev.length - 1)) { number = 1; i++; } // Add the letter for the abbreviation number += abbrev[i]; // We are done... stop break; } } return number;}Outputs:
abbrNum(12 , 1) => 12abbrNum(0 , 2) => 0abbrNum(1234 , 0) => 1kabbrNum(34567 , 2) => 34.57kabbrNum(918395 , 1) => 918.4kabbrNum(2134124 , 2) => 2.13mabbrNum(47475782130 , 2) => 47.48b
var pow = Math.pow, floor = Math.floor, abs = Math.abs, log = Math.log;var abbrev = 'kmb'; // could be an array of strings: [' m', ' Mo', ' Md']function round(n, precision) { var prec = Math.pow(10, precision); return Math.round(n*prec)/prec;}function format(n) { var base = floor(log(abs(n))/log(1000)); var suffix = abbrev[Math.min(2, base - 1)]; base = abbrev.indexOf(suffix) + 1; return suffix ? round(n/pow(1000,base),2)+suffix : ''+n;}Demo:
> tests = [-1001, -1, 0, 1, 2.5, 999, 1234, 1234.5, 1000001, Math.pow(10,9), Math.pow(10,12)]> tests.forEach(function(x){ console.log(x,format(x)) })-1001 "-1k"-1 "-1"0 "0"1 "1"2.5 "2.5"999 "999"1234 "1.23k"1234.5 "1.23k"1000001 "1m"1000000000 "1b"1000000000000 "1000b"