jQuery Traversing - Filtering
The first(), last(), eq(), filter() and not() Methods
The most basic filtering methods are first(), last() and eq(), which allow you to select a specific element based on its position in a group of elements.Other filtering methods, like filter() and not() allow you to select elements that match, or do not match, a certain criteria.
jQuery first() Method
The first() method returns the first element of the specified elements.The following example selects the first <div> element:
Example
$(document).ready(function(){
$("div").first();
}); jQuery last() Method
The last() method returns the last element of the specified elements.The following example selects the last <div> element:
Example
$(document).ready(function(){
$("div").last();
}); jQuery eq() method
The eq() method returns an element with a specific index number of the selected elements.The index numbers start at 0, so the first element will have the index number 0 and not 1. The following example selects the second <p> element (index number 1):
Example
$(document).ready(function(){
$("p").eq(1);
}); jQuery filter() Method
The filter() method lets you specify a criteria. Elements that do not match the criteria are removed from the selection, and those that match will be returned.The following example returns all <p> elements with class name "intro":
Example
$(document).ready(function(){
$("p").filter(".intro");
}); jQuery not() Method
The not() method returns all elements that do not match the criteria.Tip: The not() method is the opposite of filter().
The following example returns all <p> elements that do not have class name "intro":
Example
$(document).ready(function(){
$("p").not(".intro");
}); 
