title: The invocation context (this) of the forEach function call
body: <p>I was wondering what the 'this' value (or invocation context) is of the forEach callback function. This code doesn't seem to work:</p>
  
  <pre><code>var jow = [5, 10, 45, 67];
  
  jow.forEach(function(v, i, a){
  
      this[i] = v + 1;
  
  });
  
  alert(jow);
  </code></pre>
  
  <p>Thx for explaining it to me.</p>