insert-comma-delimiter.js: 小数or整数文字列に3桁区切りでカンマを挿入します。

insert-comma-delimiter.js

/**
 * insert-comma-delimiter.js
 * Insert commas in a numeric string.
 *
 * @version 1.0.1
 * @author think49
 * @url https://gist.github.com/think49/c13758815bc0af4b19e3
 * @license http://www.opensource.org/licenses/mit-license.php (The MIT License)
 */

'use strict';

/**
 * insert comma delimiter
 * @function
 * @param  {String} numberString Numeric string of decimal or integer.
 * @return {String} Numeric string of comma-separated.
 */
function insertCommaDelimiter (numberString) {
  return numberString.replace(/(\d+)(\.\d+)?/, function (subString, capture1, capture2) {
    capture1 = capture1.split(/(?=(?:\d{3})+$)/).join();
    return capture2 ? capture1 + capture2.replace(/(\d{3})(?=\d)/, '$1,') : capture1;
  });
}