to-zero-padding.js : 数値をゼロパディングされた数値文字列に変換する

to-zero-padding.js

/**
 * to-zero-padding.js
 * The Number value is changed to the numerical string value of zero padding.
 *
 * @version 1.1.1
 * @author think49
 * @url https://gist.github.com/891983
 * @license http://www.opensource.org/licenses/mit-license.php (The MIT License)
 */

'use strict';
var toZeroPadding = (function (Number, isNaN, Array) {
  'use strict';

  function toZeroPadding (number, limit) {
    number = Number(number);

    if (isNaN(number)) {
      return null;
    }

    return (Array(limit).join('0') + number).slice(-limit);
  }

  return toZeroPadding;
})(Number, isNaN, Array);

コードサンプル

alert(toZeroPadding(1, 2));  // "01"
alert(toZeroPadding(2, 3));  // "002"
alert(toZeroPadding(30, 3)); // "030"