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    <blockquote> <p>How should this be constructed so onclick events function as they do in the first method?</p> <p>Uncaught TypeError: Object # has no method 'addEventListener'</p> </blockquote> <p>That's obcously the reason. You need to add the event listenere to a DOM element, so you could do for example:</p> <pre><code>var clickMe = new CountMe(); document.getElementById("square").addEventListener("click", clickMe.countClick, false); </code></pre> <p>The variable <code>elt</code> is, as correctly commented, privately scoped and cannot be accessed from outside. That means you just should move the add-process into the constructor (if the element is determinable), or drop it at all.</p> <blockquote> <p>In the method countClick what context is the nested this in? The instance of the CountMe class I suspect, just want someone else's take.</p> </blockquote> <p>That depends on the calling. With your code</p> <pre><code>clickMe.countClick(); </code></pre> <p>the instance <code>clickMe</code> would be the context, but when the function is called as an event listener the DOM element will be the context. See MDN's overview for the <a href="https://developer.mozilla.org/en/JavaScript/Reference/Operators/this" rel="nofollow noreferrer"><code>this</code> keyword</a>. You can use a closure-scoped variable to hold a reference to the actual instance, as for example described <a href="https://stackoverflow.com/questions/1081499/accessing-an-objects-property-from-an-event-listener-call-in-javascript?lq=1">here</a> (there are many questions about that).</p> <p>Three possible quick-fixes:</p> <ul> <li><code>domel.addEventListener("click", clickMe.countClick.bind(clickMe), false)</code></li> <li><code>domel.addEventListner("click", function(){clickMe.countClick();}, false)</code></li> <li><code>var that=this; this.countClick=function(){ that.addCount(); alert(); };</code></li> </ul>
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    1. POHow Do I Access Event Listeners on an instance of class?
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    1. COI will give the links a look. I've updated my code example and now I get the following error `Uncaught TypeError: Object #<HTMLDivElement> has no method 'addCount'`. Can you fiddle a working answer based on your comment?
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    2. COYes, that's now the problem/feature that the context is the DivElement not the CountMe instance.
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    3. COI have outlined the possible solutions, though probably you would have found and understood them yourself when reading about the problem.
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