title: JavaScript Only Image Hover
body: <p>This is purely for learning purposes; I know that CSS would be the preferred method for this situation.</p>
  
  <p>I know that in JavaScript, you can use inline event handling to hover over an image, like so:</p>
  
  <pre><code>&lt;img src="image.png" onMouseover="src='image2.png'" onMouseout="src='image.png'"&gt;
  </code></pre>
  
  <p>And I know you can install jQuery in your site, and do the following code or similar:</p>
  
  <p>HTML:</p>
  
  <pre><code>&lt;img src="image.png" id="image-hover"&gt;
  </code></pre>
  
  <p>jQuery:</p>
  
  <pre><code>$(document).ready(function() {
          $( "#hover-example" ).mouseover(function(){
              $(this).attr("src", "image-hover.png");
          });
  
          $( "#hover-example" ).mouseout(function(){
              $(this).attr("src", "image.png");
          });
      });
  </code></pre>
  
  <p>I was wondering how one would use JavaScript-only to produce that output, but use an external script instead of inline event handling. I've tried browsing through various Stack Overflow and Google searches, but mostly they lead to using jQuery instead. Could it be that complicated to apply that simple inline JavaScript to an external script?</p>
  
  <p>Thanks!</p>