Format a number as 2.5K if a thousand or more, oth

Question

I need to show a currency value in the format of 1K of equal to one thousand, or 1.1K, 1.2K, 1.9K etc, if its not an even thousands, otherwise if under a thousand, display normal 500, 100, 250 etc, using javascript to format the number?

Answer 1

This post is quite old but I somehow reached to this post searching for something. SO to add my input Numeral js is the one stop solution now a days. It gives a large number of methods to help formatting the numbers

http://numeraljs.com/

Answer 2

/*including negative values*/    
function nFormatter(num) {
      let neg = false;
       if(num < 0){
         num = num * -1;
         neg = true;
       }
       if (num >= 1000000000) {
         if(neg){
           return -1 * (num / 1000000000).toFixed(1).replace(/\.0$/, '') + 'G';  
         }
         return (num / 1000000000).toFixed(1).replace(/\.0$/, '') + 'G';
       }
       if (num >= 1000000) {
         if(neg){
           return -1 * (num / 1000000).toFixed(1).replace(/\.0$/, '') + 'M';  
         }
         return (num / 1000000).toFixed(1).replace(/\.0$/, '') + 'M';
       }
       if (num >= 1000) {
         if(neg){
           return -1 * (num / 1000).toFixed(1).replace(/\.0$/, '') + 'K';  
         }
         return (num / 1000).toFixed(1).replace(/\.0$/, '') + 'K';
       }
       return num;
    }

Answer 3

A more generalized version:

function nFormatter(num, digits) {
  var si = [
    { value: 1, symbol: "" },
    { value: 1E3, symbol: "k" },
    { value: 1E6, symbol: "M" },
    { value: 1E9, symbol: "G" },
    { value: 1E12, symbol: "T" },
    { value: 1E15, symbol: "P" },
    { value: 1E18, symbol: "E" }
  ];
  var rx = /\.0+$|(\.[0-9]*[1-9])0+$/;
  var i;
  for (i = si.length - 1; i > 0; i--) {
    if (num >= si[i].value) {
      break;
    }
  }
  return (num / si[i].value).toFixed(digits).replace(rx, "$1") + si[i].symbol;
}

/*
 * Tests
 */
var tests = [
  { num: 1234, digits: 1 },
  { num: 100000000, digits: 1 },
  { num: 299792458, digits: 1 },
  { num: 759878, digits: 1 },
  { num: 759878, digits: 0 },
  { num: 123, digits: 1 },
  { num: 123.456, digits: 1 },
  { num: 123.456, digits: 2 },
  { num: 123.456, digits: 4 }
];
var i;
for (i = 0; i < tests.length; i++) {
  console.log("nFormatter(" + tests[i].num + ", " + tests[i].digits + ") = " + nFormatter(tests[i].num, tests[i].digits));
}

Answer 4

Further improving Salman's Answer because it returns nFormatter(33000) as 33.0K

function nFormatter(num) {
     if (num >= 1000000000) {
        return (num / 1000000000).toFixed(1).replace(/\.0$/, '') + 'G';
     }
     if (num >= 1000000) {
        return (num / 1000000).toFixed(1).replace(/\.0$/, '') + 'M';
     }
     if (num >= 1000) {
        return (num / 1000).toFixed(1).replace(/\.0$/, '') + 'K';
     }
     return num;
}

now nFormatter(33000) = 33K

Answer 5

• Support negative number
• Checking for !Number.isFinite
• Change ' K M G T P E Z Y' to ' K M' if you want the max unit is M

---

Number.prototype.prefix = function (precision = 2) {

    var units = ' K M G T P E Z Y'.split(' ');

    if (this < 0) {
        return '-' + Math.abs(this).prefix(precision);
    }

    if (this < 1) {
        return this + units[0];
    }

    var power = Math.min(
        Math.floor(Math.log(this) / Math.log(1024)),
        units.length - 1
    );

    return (this / Math.pow(1024, power)).toFixed(precision) + units[power];
}

(10240).prefix() // 10.00K
(1234000).prefix(1) // 1.2M
(-10000).prefix() // -9.77K

Answer 6

Adding on the top answer, this will give 1k for 1000 instead of 1.0k

function kFormatter(num) {
    return num > 999 ? num % 1000 === 0 ? (num/1000).toFixed(0) + 'k' : (num/1000).toFixed(1) + 'k' : num
}