Question

30

addEventListener calls the function without me even asking it to

rated 0 times [ 34] [ 4] / answers: 1 / hits: 57525 / 11 Years ago, tue, april 30, 2013, 12:00:00

So we have a page:

<span id='container'>

    <a href='#' id='first'>First Link</a>

    <a href='#' id='second'>Second Link</a>

</span>

And want to add some click events:

first.addEventListener('click', function(){alert('sup!');})

Works like a charm! However, when you make the second argument an external function:

function message_me(m_text){

    alert(m_text)

}



second.addEventListener('click', message_me('shazam'))

It calls the function immediately. How can I stop this? So annoying!

Here's a live demo: http://jsfiddle.net/ey7pB/1/

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roberts

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answered 11 Years ago ellisc · Accepted Answer

Quoting Ian's answer:

Since the second parameter expects a function reference, you need to provide one. With your problematic code, you're immediately calling the function and passing its result (which is undefined...because all the function does is alert and doesn't return anything). Either call the function in an anonymous function (like your first example) or alter the function to return a function.

function message_me(m_text){

    alert(m_text)

} 



second.addEventListener('click', 

    function() {

        message_me('shazam');

    }

);

Here's an updated fiddle.