How to alert using jQuery

Question

This works:

$(\'.overdue\').addClass(\'alert\');

But this doesn\'t:

$(\'.overdue\').alert(\'Your book is overdue.\'); 
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Answer 1

Don't do this, but this is how you would do it:

$(".overdue").each(function() { 
    alert("Your book is overdue"); 
});

The reason I say "don't do it" is because nothing is more annoying to users, in my opinion, than repeated pop-ups that cannot be stopped. Instead, just use the length property and let them know that "You have X books overdue".

Answer 2

$(".overdue").each( function() {
    alert("Your book is overdue.");
});

Note that ".addClass()" works because addClass is a function defined on the jQuery object. You can't just plop any old function on the end of a selector and expect it to work.

Also, probably a bad idea to bombard the user with n popups (where n = the number of books overdue).

Perhaps use the size function:

alert( "You have " + $(".overdue").size() + " books overdue." );

Answer 3

For each works with JQuery as in

$(<selector>).each(function() {
   //this points to item
   alert('<msg>');
});

JQuery also, for a popup, has in the UI library a dialog widget: http://jqueryui.com/demos/dialog/

Check it out, works really well.

HTH.