问题
I have a habbit of debugging JS and jQuery script in some developer tool. I realized Chrome Dev Tools showing x.fn.x.init as a value for $() and $(this). However I dont realize what are these value:
Code
<!DOCTYPE html>
<html lang="en" xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="utf-8" />
<script src="jquery-2.0.2.min.js" ></script>
<script src="jquery.ui.widget.js" ></script>
<title></title>
<script type="text/javascript">
$(document).ready(function () {
var outstring = "";
outstring = "" + $() + $(this);
});
</script>
</head>
<body>
</body>
</html>
回答1:
This is actually the REAL code behind instantiating $
Take a look at the github source
jQuery.fn = jQuery.prototype = {
// The current version of jQuery being used
jquery: core_version,
constructor: jQuery,
init: function( selector, context, rootjQuery ) {
var match, elem;
.....
and then at line 263
// Give the init function the jQuery prototype for later instantiation
jQuery.fn.init.prototype = jQuery.fn;
Since you are using the minified version, this gets turned into what you see.
来源：https://stackoverflow.com/questions/17858153/what-is-x-fn-x-init-value-shown-for-and-this-in-chrome-dev-tools