title: How do you use underscore's chain method to return the first item in a multidimensional array?
body: <p>Say I have an array of arrays, and I want to return the first element of each array within the array:</p>
  
  <pre><code>array = [[["028A","028B","028C","028D","028E"],
            ["028F","0290","0291","0292","0293"],
            ["0294","0295","0296","0297","0298"],
            ["0299","029A","029B","029C","029D"],
            ["029E","029F","02A0","02A1","02A2"]],
           [["02A3","02A4"],
            ["02A5", "02A6"]];
  </code></pre>
  
  <p>I know I can do something like this:</p>
  
  <pre><code>var firsts = [];
  _.each(array, function(item){
    _.each(item, function(thisitem){
      firsts.push(_.first(thisitem));
    });
  });
  </code></pre>
  
  <p>but what if I want to do it with underscore's <code>_.chain()</code> method? Just learning underscore, and so far seems very useful.</p>