jQuery Selectors

jQuery selectors are one of the most important parts of the jQuery library.
jQuery Selectors
jQuery selectors allow you to select and manipulate HTML element(s).
With jQuery selectors you can find elements based on their id, classes, types, attributes, values of attributes and much more. It's based on the existing CSS Selectors, and in addition, it has some own custom selectors.
All type of selectors in jQuery, start with the dollar sign and parentheses: $().

The element Selector
The jQuery element selector selects elements based on their tag names.

You can select all <p> elements on a page like this:
$("p")
Example
When a user clicks on a button, all <p> elements will be hidden:

$(document).ready(function(){

$("button").click(function(){

$("p").hide(); }); });

The #id Selector

The jQuery #id selector uses the id attribute of an HTML tag to find the specific element.
An id should be unique within a page, so you should use the #id selector when you want to find a single, unique element.

To find an element with a specific id, write a hash character, followed by the id of the element:

$("#test")

Example
When a user clicks on a button, the element with id="test" will be hidden:

$(document).ready(function(){

$("button").click(function(){

$("#test").hide();

});

});

The .class Selector

The jQuery class selector finds elements with a specific class.
To find elements with a specific class, write a period character, followed by the name of the class:
$(".test")

Example
When a user clicks on a button, the elements with class="test" will be hidden:

$(document).ready(function(){

$("button").click(function(){

$(".test").hide(); }); });

More Examples of jQuery Selectors

         Syntax                                                       Description                                 
$("*")                                           Selects all elements
$(this)                                          Selects the current HTML element
$("p.intro")                                  Selects all <p> elements with class="intro"
$("p:first")                                   Selects the first <p> element
$("ul li:first")                               Selects the first <li> element of the first <ul>
$("ul li:first-child")                      Selects the first <li> element of every <ul>
$("[href]")                                    Selects all elements with an href attribute
$("a[target='_blank']")                Selects all <a> elements with a target                                              attribute value equal to "_blank"   

 $("a[target!='_blank']")               Selects all <a> elements with a target                   

                                                       attribute value NOT equal to "_blank"

$(":button")                                  Selects all <button> elements and <input>                                                         elements of type="button"
$("tr:even")                                   Selects all even <tr> elements
$("tr:odd")                                    Selects all odd <tr> elements