...onclick =Null;

[QuakeLive]

Hi,

 

I have a question about Creating Modal Windows example... Quote:

 

 

function openModal() {
    'use strict';
    document.getElementById('closeModal').onclick = closeModal;
    document.getElementById('modal').style.display = 'inline-block';
    document.getElementById('openModal').onclick = null;
}

function closeModal() {
    'use strict';
    document.getElementById('openModal').onclick = openModal;
    document.getElementById('modal').style.display = 'none';
    document.getElementById('closeModal').onclick = null;
}

window.onload = function() {
    'use strict';
    document.getElementById('openModal').onclick = openModal;
};

 

If I remove the following lines (altogether, all three lines):

• In function openModal(): document.getElementById('openModal').onclick = null;
• In function closeModal(): document.getElementById('openModal').onclick = openModal;
• In function closeModal(): document.getElementById('closeModal').onclick = null;

so that the new code looks like this:

 

 

function openModal() {
    'use strict';
    document.getElementById('closeModal').onclick = closeModal;
    document.getElementById('modal').style.display = 'inline-block';
}

function closeModal() {
    'use strict';
    document.getElementById('modal').style.display = 'none';
}

window.onload = function() {
    'use strict';
    document.getElementById('openModal').onclick = openModal;
};

 

everything works well, there are no errors. I don't understand why there are these three lines?

 

Thank you in advance!

[Larry]

The point of those lines is to drop event handlers when they're not needed. This is a tidiness issue, that's not required, and won't affect the functionality, but is arguably more professional and can prevent memory leaks.

[QuakeLive]

Ok, thank you very much!