1  /*!
 2   * is-number <https://github.com/jonschlinkert/is-number>
 3   *
 4   * Copyright (c) 2014-2015, Jon Schlinkert.
 5   * Licensed under the MIT License.
 6   */
 7  
 8  'use strict';
 9  
10  var typeOf = require('kind-of');
11  
12  module.exports = function isNumber(num) {
13    var type = typeOf(num);
14  
15    if (type === 'string') {
16      if (!num.trim()) return false;
17    } else if (type !== 'number') {
18      return false;
19    }
20  
21    return (num - num + 1) >= 0;
22  };