percentage-calc.js

/**
 * Percentage-Calc 0.0.1
 * https://github.com/abpetkov/percentage-calc
 *
 * Authored by Alexander Petkov
 * https://github.com/abpetkov
 *
 * Copyright 2014, Alexander Petkov
 * License: The MIT License (MIT)
 * http://opensource.org/licenses/MIT
 *
 */

/**
 * Check if number.
 *
 * @param {Number} num
 * @returns {Boolean}
 * @api public
 */

exports.isNumber = function(num) {
  return (typeof num === 'number') ? true : false;
};

/**
 * Calculate percentage of a number.
 *
 * @param {Number} perc
 * @param {Number} num
 * @returns {Number} result
 * @api public
 */

exports.of = function(perc, num) {
  if (exports.isNumber(perc) && exports.isNumber(num)) return (perc / 100) * num;
};

/**
 * Calculate percentage of a number out ot another number.
 *
 * @param {Number} part
 * @param {Number} target
 * @returns {Number} result
 * @api public
 */

exports.from = function(part, target) {
  if (exports.isNumber(part) && exports.isNumber(target)) return (part / target) * 100;
};