jQuery in Action, Страница 195

jQuery in Action

166

CHAPTER 6

jQuery utility functions

var $ = 'Hi!';

jQuery(function(){

alert('$ = '+ $);

});

</script>

</head>

<body>

</body>

</html>

In this document, we import jQuery, which (as we know) defines the global names

jQuery

and its alias

. We then redefine the global

name to a string value

overriding the jQuery definition. We replace

with a simple string value for sim-

plicity within this example, but it could be redefined by including another library
such as Prototype.

We then define the ready handler

whose only action is to display an alert

showing the value of

When we load this page, we see the alert displayed, as shown in figure 6.3.
Note that, within the ready handler, the global value of

is in scope and has the

expected value resulting from our string assignment. How disappointing if we
only wanted to use the jQuery definition of

within the handler.

Now let's make one change to this example document. Listing 6.3 shows only

the portion of the document that has been modified; the minimal change is high-
lighted in bold.

Overrides $ name
with custom value

Declares the
ready handler

Figure 6.3 The

says, "Hi!" as its redefinition takes effect within the ready handler.