title: Accessing nested JavaScript objects and arrays by string path
body: <p>I have a data structure like this :</p>
  
  <pre><code>var someObject = {
      'part1' : {
          'name': 'Part 1',
          'size': '20',
          'qty' : '50'
      },
      'part2' : {
          'name': 'Part 2',
          'size': '15',
          'qty' : '60'
      },
      'part3' : [
          {
              'name': 'Part 3A',
              'size': '10',
              'qty' : '20'
          }, {
              'name': 'Part 3B',
              'size': '5',
              'qty' : '20'
          }, {
              'name': 'Part 3C',
              'size': '7.5',
              'qty' : '20'
          }
      ]
  };
  </code></pre>
  
  <p>And I would like to access the data using these variable :</p>
  
  <pre><code>var part1name = "part1.name";
  var part2quantity = "part2.qty";
  var part3name1 = "part3[0].name";
  </code></pre>
  
  <p>part1name should be filled with <code>someObject.part1.name</code> 's value, which is "Part 1". Same thing with part2quantity which filled with 60.</p>
  
  <p>Is there anyway to achieve this with either pure javascript or JQuery?</p>