yiyunjianzhuBeta/node_modules/is-number/index.js

/*!
 * is-number <https://github.com/jonschlinkert/is-number>
 *
 * Copyright (c) 2014-2015, Jon Schlinkert.
 * Licensed under the MIT License.
 */

'use strict';

var typeOf = require('kind-of');

module.exports = function isNumber(num) {
  var type = typeOf(num);

  if (type === 'string') {
    if (!num.trim()) return false;
  } else if (type !== 'number') {
    return false;
  }

  return (num - num + 1) >= 0;
};