Why Is My removeEventListener Not Working in JavaScript?

Javascript removeEventListener Not Working

In the realm of event handling, the removeEventListener method plays a crucial role in detaching event listeners from elements. However, encountering issues with removeEventListener not functioning as anticipated can be frustrating.

Consider the following code snippet:

<code class="javascript">area.addEventListener('click',function(event) {
    app.addSpot(event.clientX,event.clientY);
    app.addFlag = 1;
},true);</code>

This code proficiently attaches an anonymous function as an event listener for the 'click' event on the 'area' element. However, when attempting to remove this listener with the following code:

<code class="javascript">area.removeEventListener('click',function(event) {
    app.addSpot(event.clientX,event.clientY);
    app.addFlag = 1;
},true);</code>

You may encounter a roadblock. The problem lies in the distinct nature of the anonymous functions used in addEventListener and removeEventListener. The function provided as an argument to removeEventListener is not identical to the previously registered function. To resolve this issue, assign the listener function to a named variable:

<code class="javascript">function foo(event) {
    app.addSpot(event.clientX,event.clientY);
    app.addFlag = 1;
}
area.addEventListener('click',foo,true);
area.removeEventListener('click',foo,true);</code>

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