php if - 屏幕宽度 - 加载js

Question

I'm new to php. I have a doubt, don't know if this can be done, or if it should be done in another way or what. I want to load a JS only if the screen size is higher than x size.

I wrote this but the JS is not being loaded (in fact I want to load a couple of JS):

<script language="javascript">
if (screen.width > 549) {
    <script src='js/jquery-1.8.1.min.js' type='text/javascript'></script>
}

best regards!

Answer 1

It's cleaner to detect the screen width in JavaScript. Also remember the screensize can change in a session. For example when a user resizes his screen.

Use this in your JavaScript file:

var width = document.body.clientWidth;
if(width > 549) {

} else if(width < 300) {

} else {

}