title: What does map(Number) do here?
body: <pre><code>var strArr = ["[1,2,3,4]","[1,2,3,4"]];
  var arr1 = strArr[0].match(/\d+/g).map(Number); 
  </code></pre>
  
  <p>I know that the <code>map()</code> method creates a new array with the results of calling a provided function on every element in the calling array. Here as <code>Number</code> is a wrapper object I am not able to understand what's going on.</p>
  
  <p>What I understood is that if I console log removing the map method I get an array of strings whereas including the map method I get an array of numbers.I would like to know how map is able to take each string and converting to number.</p>