Checking if jquery is loaded using Javascript
I am attempting to check if my Jquery Library is loaded onto my HTML page. I am checking to see if it works, but something is not right. Here is what I have:
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<script type="text/javascript" src="/query-1.6.3.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
if (jQuery) {
// jQuery is loaded
alert("Yeah!");
} else {
// jQuery is not loaded
alert("Doesn't Work");
}
});
</script>
Solution 1:
something is not right
Well, you are using jQuery to check for the presence of jQuery. If jQuery isn't loaded then $() won't even run at all and your callback won't execute, unless you're using another library and that library happens to share the same $() syntax.
Remove your $(document).ready() (use something like window.onload instead):
window.onload = function() {
if (window.jQuery) {
// jQuery is loaded
alert("Yeah!");
} else {
// jQuery is not loaded
alert("Doesn't Work");
}
}
Solution 2:
As per this link:
if (typeof jQuery == 'undefined') {
// jQuery IS NOT loaded, do stuff here.
}
there are a few more in comments of the link as well like,
if (typeof jQuery == 'function') {...}
//or
if (typeof $== 'function') {...}
// or
if (jQuery) {
alert("jquery is loaded");
} else {
alert("Not loaded");
}
Hope this covers most of the good ways to get this thing done!!
Solution 3:
if ('undefined' == typeof window.jQuery) {
// jQuery not present
} else {
// jQuery present
}
Solution 4:
You can do this fast on the console-tab when inspecting your webpage.
E.g:
$ === jQuery
If it returns true it means it's loaded.
Solution 5:
Just a small modification that might actually solve the problem:
window.onload = function() {
if (window.jQuery) {
// jQuery is loaded
alert("Yeah!");
} else {
location.reload();
}
}
Instead of $(document).Ready(function() use window.onload = function().