How to format numbers similar to Stack Overflow reputation format

I want to convert a number into a string representation with a format similar to Stack Overflow reputation display.

e.g.

• 999 == '999'
• 1000 == '1,000'
• 9999 == '9,999'
• 1000开发者_C百科0 == '10k'
• 10100 == '10.1k'

---

Another approach that produces exactly the desired output:

function getRepString (rep) {
  rep = rep+''; // coerce to string
  if (rep < 1000) {
    return rep; // return the same number
  }
  if (rep < 10000) { // place a comma between
    return rep.charAt(0) + ',' + rep.substring(1);
  }
  // divide and format
  return (rep/1000).toFixed(rep % 1000 != 0)+'k';
}

Check the output results here.

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UPDATE: CMS got the check and provides a superior answer. Send any more votes his way.

// formats a number similar to the way stack exchange sites 
// format reputation. e.g.
// for numbers< 10000 the output is '9,999'
// for numbers > 10000 the output is '10k' with one decimal place when needed
function getRepString(rep)
{
    var repString;

    if (rep < 1000)
    {
        repString = rep;
    }
    else if (rep < 10000)
    {
        // removed my rube goldberg contraption and lifted
        // CMS version of this segment
        repString = rep.charAt(0) + ',' + rep.substring(1);
    }
    else
    {
        repString = (Math.round((rep / 1000) * 10) / 10) + "k"
    }

    return repString.toString();
}

Output:

• getRepString(999) == '999'
• getRepString(1000) == '1,000'
• getRepString(9999) == '9,999'
• getRepString(10000) == '10k'
• getRepString(10100) == '10.1k'

---

Here is a function in PHP which is part of iZend - http://www.izend.org/en/manual/library/countformat:

function count_format($n, $point='.', $sep=',') {
    if ($n < 0) {
        return 0;
    }

    if ($n < 10000) {
        return number_format($n, 0, $point, $sep);
    }

    $d = $n < 1000000 ? 1000 : 1000000;

    $f = round($n / $d, 1);

    return number_format($f, $f - intval($f) ? 1 : 0, $point, $sep) . ($d == 1000 ? 'k' : 'M');
}

---

Here is CMS's version in PHP (in case someone needed it, like I did):

function getRepString($rep) {
    $rep = intval($rep);
    if ($rep < 1000) {
        return (string)$rep;
    }
    if ($rep < 10000) {
        return number_format($rep);
    }
    return number_format(($rep / 1000), ($rep % 1000 != 0)) . 'k';
}

// TEST
var_dump(getRepString(999));
var_dump(getRepString(1000));
var_dump(getRepString(9999));
var_dump(getRepString(10000));
var_dump(getRepString(10100));

Output:

string(3) "999"
string(5) "1,000"
string(5) "9,999"
string(3) "10k"
string(5) "10.1k"

---

 Handlebars.registerHelper("classNameHere",function(rep) {
    var repString;
       if (rep < 1000)
    {
        repString = rep;
    }
    else if (rep < 10000)
    {
        rep = String(rep);
        r = rep.charAt(0);
        s = rep.substring(1);
        repString =  r + ',' + s;
    }
    else
    {
        repDecimal = Math.round(rep / 100) / 10;
        repString = repDecimal + "k";
    }
       return repString.toString();
   });

---

divide by 1000 then if result is greater than 1 round the number and concantenate a "k" on the end.

If the result is less than 1 just output the actual result!

---

// Shortens a number and attaches K, M, B, etc. accordingly
function number_shorten($number, $precision = 3, $divisors = null) {

    // Setup default $divisors if not provided
    if (!isset($divisors)) {
        $divisors = array(
            pow(1000, 0) => '', // 1000^0 == 1
            pow(1000, 1) => 'K', // Thousand
            pow(1000, 2) => 'M', // Million
            pow(1000, 3) => 'B', // Billion
            pow(1000, 4) => 'T', // Trillion
            pow(1000, 5) => 'Qa', // Quadrillion
            pow(1000, 6) => 'Qi', // Quintillion
        );    
    }

    // Loop through each $divisor and find the
    // lowest amount that matches
    foreach ($divisors as $divisor => $shorthand) {
        if (abs($number) < ($divisor * 1000)) {
            // We found a match!
            break;
        }
    }

    // We found our match, or there were no matches.
    // Either way, use the last defined value for $divisor.
    return number_format($number / $divisor, $precision) . $shorthand;
}

This worked for me. I hope, this will help you. Thanks for asking this question.

---

I created an npm (and bower) module to do this:

npm install --save approximate-number

Usage:

var approx = require('approximate-number');
approx(123456); // "123k"