Pro PHP and jQuery by Jason Lengstorf.pdf - Computer Science ...

CHAPTER 2 ■ COMMON JQUERY ACTIONS AND METHODS
To select the same paragraph as the preceding example by counting backward from the end of the
result set, use the following code:
$("p").eq(-3);
This returns the same paragraph in the console:
>>> $("p").eq(-3);
[ p.foo ]
.filter() and .not()
To use a whole new selector within a set of elements, the .filter() method comes in handy. It accepts
any selector that can be used in the jQuery function, but it applies only to the subset of elements
contained within the jQuery object.
For instance, to select all paragraphs and then filter out all but the ones with class foo, you would
use the following:
$("p").filter(".foo");
The result in the console will read as follows:
>>> $("p").filter(".foo");
[ p.foo ]
The inverse of .find() is .not(), which will return all elements from a result set that do not match
the given selector. For instance, to select all paragraphs and then limit the selection to paragraphs that
do not have the class foo, you would use the following:
$("p").not(".foo");
This results in the following:
>>> $("p").not(".foo");
[ p, p, p#bar ]
.first() and .last()
The .first() and .last() methods work identically to .eq(0) and .eq(-1), respectively. To select the
last paragraph from a set of all paragraphs on the page, use the following:
$("p").last();
This results in the following:
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