When we use alert(), some times the code breaks.

For example:

HTML:

<span>Hi</span>

Javascript:

$(document).ready(function () {



    $(span).dblclick(function () {

        alert(b);

    });

    $(span).click(function () {

        alert(a);

    });



});

The alert(b) doesn't even show up.

But if we change both the alert() to console.log, it is logged.

Alert Demo & console.log Demo

So, what's happening?