jquery and JS specific use of the difference (incomplete, beginner)

jquery can greatly simplify the writing of JavaScript programs

To use jquery, first add a reference to the jquery library in front of the HTML code, such as:

<script language= "javascript" src= "/js/jquery.min.js" ></script>

     library files can be either local or directly use the CDN of a well-known company, the advantage is that these large companies are more popular CDN, users visit your site before it is likely to visit other sites have been cached in the browser, so it can speed up the opening of the site. Another benefit is obvious, saving the traffic bandwidth of the website.

The specific wording of the jquery code and the native JavaScript notation differ from the following when performing common operations:

1 positioning elements JS document.getElementById ("abc")
jQuery $ ("#abc") by ID locating $ (". ABC") by using the class Locator $ ("div") via tag positioning
It is important to note that the result of JS return is this element, jquery returns the result is a JS object. The following example assumes that element ABC has been positioned.  
2 Changing the contents of an element

      js  abc.innerhtml = "Test"; &NBSP; jquery&NBSP; abc.html (" test "); Span class= "Apple-converted-space" >&NBSP;
3 Show hidden elements &NBSP;

     js  abc.style.display = "None"; &NBSP; abc.style.display =" block "; &NBSP;
     jquery&NBSP; abc.hide (); &NBSP; abc.show ();

Abc.toggle (); / /toggle between display and hide
4 getting focus
JS and jquery are the same, both Abc.focus ();  
5 Assigning a value to a form

     js  abc.value = "Test"; &NBSP; jquery&NBSP; Abc.val ("test"); &NBSP;
6 Gets the value of the form &NBSP;

     js&NBSP; alert (abc.value); &NBSP; jquery&NBSP; alert (Abc.val ()); Span class= "Apple-converted-space" >&NBSP;
7 set element is not available &NBSP;

     js  abc.disabled = true; &NBSP; jquery&NBSP; Abc.attr ("Disabled", true);

8 Modifying element styles

JS abc.style.fontsize=size; JQuery abc.css (' font-size ', 20);

JS abc.classname= "Test"; JQuery Abc.removeclass (); abc.addclass ("test");

9 Ajax

JS to create their own objects, handle browser compatibility and other messy problems, omit the table

JQuery $.get ("abc.php?a=1&b=2", recall);

Postvalue = "a=b&c=d&abc=123";

$.post ("abc.php", Postvalue, Recall);

       function Recall (Result) {alert (Result) and//If JSON is returned, the

is processed as follows

result = eval (' (' + result + ') ');  

alert (result); }

10 Determine if check box is selected

JQuery if (abc.attr ("checked") = = "Checked")

Note: Online said. attr ("checked") = = true is not actually used, the above test can be used