How to format numbers similar to Stack Overflow reputation format

Question

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

e.g.

• 999 == \'999\'
• 1000 =

Answer 1

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"