/**
* Pad zero to strings.
* @function lib.string.padZero
* @param {string|number} number - Number string to pad.
* @param {number} digit - Digit to pad.
* @returns {string} - Padded string
* @author Taka Okunishi
*
*/
module.exports = function (number, digit) {
var padded = String(number);
while (padded.length < digit) {
padded = "0" + padded;
}
return padded;
};