pads string with specified character, with defined length

padString.js

/* padString.js - pads string with specified character, with defined length
 * @author - Livingston Samuel
 */

var padString = function (str, char, len) {
    if (arguments.length !== 3 || String(char).length !== '' || str.length >= len) {
        return str;
    }

    var l = str.length;

    while (l++ < len) {
        str = char + str;
    }

    return str;
};

String.pad.js

/* String.pad.js - String prototype method to pad string with specified character, with defined length
 * @author - Livingston Samuel
 */

String.prototype.pad = function (char, len) {
    var str = this, l = str.length;
	
    if (arguments.length !== 2 || String(char).length !== 1 || str.length >= len) {
        return str;
    }

    while (l++ < len) {
        str = char + str;
    }

    return str;
};