Javascript Date: Ensure getMinutes(), getHours(), getSeconds() puts 0 in front if necessary

Similar to @jdmichal's solution, posting because I'd prefer something a little shorter:

function pad(n) { return ("0" + n).slice(-2); }

pad(6); // -> "06"
pad(12); // -> "12"

Rather than add individual methods to Date.prototype, you could just add this method to Number.prototype:

Number.prototype.pad = function (len) {
    return (new Array(len+1).join("0") + this).slice(-len);
}

// Now .pad() is callable on any number, including those returned by
var time = date.getHours().pad(2) + ":"
         + date.getMinutes().pad(2) + ":"
         + date.getSeconds().pad(2);

Update: ECMAScript 2017 (ECMA-262)

padStart has been added to pad the beginning of a string with another string, where the first value is the length it should be and the second value being what to pad it with.

For example:

let d = new Date()
let h = `${d.getHours()}`.padStart(2, '0')
let m = `${d.getMinutes()}`.padStart(2, '0')
let s = `${d.getSeconds()}`.padStart(2, '0')

let displayDate = h + ":" + m + ":" + s
// Possible Output: 09:01:34

---

Pre-ECMAScript 2017

As far as I know, there's not. And I do this all the time for converting dates to the XML dateTime format.

It's also important to note that those methods you list return a number, not a string.

You can, of course, add these yourself by modifying Date.prototype.

Date.prototype.getHoursTwoDigits = function()
{
    var retval = this.getHours();
    if (retval < 10)
    {
        return ("0" + retval.toString());
    }
    else
    {
        return retval.toString();
    }
}

var date = new Date();
date.getHoursTwoDigits();

function pad2(number) {

     return (number < 10 ? '0' : '') + number

}

document.write(pad2(2) + '<br />');
document.write(pad2(10) + '<br />');

OUTPUT:

02

10