Let's say you have some hyperlinks on a page, which when clicked, will alert the user that they have clicked a hyperlink, but you only want to do it once. To ensure that the warning message appears only once, we'll have to remove the event after it has been fired.
This type of thing may be utilized for instructional tips: when the user sees an unfamiliar interface element, you can display a help tip for them, but only once, because you don't want the tip to keep showing up every single time they perform an action.
First, let's put some links on a web page.
<a href="#">Hyperlink 1</a> <a href="#">Hyperlink 2</a>
Next, let's create a function object which we will call whenever a click event happens on any of the links on our page. When the function fires, it will open up an alert box with a message, and then it will remove the click event from all
<a>elements on the web page.// Create an function object var warning = function() ...