jQuery document-ready event Difference between jQuery(fn) and executing your code before
Example
Using the document-ready event can have small performance drawbacks, with delayed execution of up to ~300ms. Sometimes the same behavior can be achieved by execution of code just before the closing </body> tag:
<body>
<span id="greeting"></span> world!
<script>
$("#greeting").text("Hello");
</script>
</body>
will produce similar behavior but perform sooner than as it does not wait for the document ready event trigger as it does in:
<head>
<script>
jQuery(function($) {
$("#greeting").text("Hello");
});
</script>
</head>
<body>
<span id="greeting"></span> world!
</body>
Emphasis on the fact that first example relies upon your knowledge of your page and placement of the script just prior to the closing </body> tag and specifically after the span tag.
