Some basic operations for assigning values to jquery forms

/* Obtain the value of text. areatext */

VaR textval = $ ("# text_id"). ATTR ("value"); // or

VaR textval = $ ("# text_id"). Val ();/* obtain the value of a single-choice button */

VaR valradio = $ ("input [@ type = radio] [@ checked]"). val ();/* Get the value of a set of Radio selected items named (items */

VaR item = $ ('input [@ name = items] [@ checked] '). Val ();/* Get the value of the check box */

VaR checkboxval = $ ("# checkbox_id"). ATTR ("value");/* Get the value of the drop-down list */

VaR selectval = $ ('# select_id'). Val (); // text box, text area:

$ ("# Text_id"). ATTR ("value", ''); // clear the content

$ ("# Text_id"). ATTR ("value", 'test'); // fill in the content

// Multiple choice box checkbox: $ ("# chk_id"). ATTR ("checked ",'');

// Make it unchecked $ ("# chk_id"). ATTR ("checked", true );

// Check if ($ ("# chk_id"). ATTR ('checked') = true)

// Determine whether or not the selected radio group is Radio:

$ ("Input [@ type = radio]"). ATTR ("checked", '2 ');

// Set the project with value = 2 as the currently selected item

// Select: $ ("# select_id"). ATTR ("value", 'test ');

// Set the project value = test as the currently selected item $ ("<option value = 'test'> test </option> <option value = 'test2'> Test2 </Option> "). appendto ("# select_id ")

// Add option $ ("# select_id"). Empty ();

// Clear the drop-down box and obtain the value of VaR item =$ ('input [@ name = items] [@ checked] ') of a set of radio items named (items). val ();

// If not selected, Val () = undefined gets the text var item of the selected select item $ ("select [@ name = items] Option [@ selected]"). text (); the second element in the select drop-down box is the currently selected value $ ('# select_id') [0]. selectedindex = 1; the second element of the radio Radio Group is the currently selected value $ ('input [@ name = items] '). get (1 ). checked = true;

// Reset the form $ ("form"). Each (function () {. Reset ();});

1. Select the element $ ("# myid"). The effect is equal to document. getelementbyid ("myid"), but the number of characters written is much less.

If you want to convert a jquery object to an HTML element, you only need to take its 0th elements. for example, $ ("# myid") returns a jquery object, while $ ("# myid") [0] returns an HTML element.
If you select all the IMG elements, write as follows: $ ("IMG ")
If you select a div element with class = "textbox" (<Div class = "textbox"> </div>), write as follows: $ ("Div. textbox ")
Select the element with the myattr attribute $ ("Div [myattr]") and select the element with the myattr attribute and the attribute value is equal to myclass $ ("Div [myattr = 'myclass']") the property is not equal to [myattr! = 'Myclass'] the attribute starts with "my" [myattr ^ = 'my'] and ends with a class. The [myattr $ = 'class'] attribute contains the following three characters: [myattr * = 'cla']
If multiple elements are returned for one selection, and you want to apply certain attributes to each element, such as background-color and background attributes f001_1_alert(%(this%.html ()); $ (this ). width ("200px ");});

2. onload event processing method $ (function () {alert ("the page structure has been loaded, but some images may not have been loaded (in general, this event is enough) ");});
You can bind multiple onload event handling methods to the page $ (function () {alert ("I was executed first ");});
$ (Function () {alert ("My second execution ");});
Bind Special Events $ ("# myid"). keydown (function () {alert ("triggered keydown event ");});
In addition to these common events, the bind method must be used to bind events.

3. element attribute/method to get the height of an element, $ ("# myid "). height () to get the position of an element, $ ("# myid "). offset () returns an offset object. If the top position of an element is obtained, $ ("# myid") is returned "). offset (). top ,? If left is left, $ ("# myid") is used "). offset (). left to get the innerhtml of an element. Then (registry.myid=}.html () to get the innertext, $ ("# myid") of an element "). text () to get the value of a text box, $ ("# myid "). val () gets the attribute of an element, $ ("# myid "). ATTR ("myattribute ")
These methods have a basic feature, that is, they do not contain a parameter to indicate a value, but contain a parameter to indicate a set value (except offset ), for example, (##myid”).height(%20″);((##myid”).html ("<a href ="> asdasd </a> ") $ (" # myid "). val ("asdasd ")
Note that offset is read-only.
Set the attribute $ ("# myid") for an element "). ATTR ("width", "20%") reads an attribute $ ("# myid "). ATTR ("width") specifies multiple attributes at a time $ ("# myid "). ATTR ({disabled: "disabled", width: "20%", height: "30"}) delete attribute $ ("# myid "). removeattr ("disabled ")
Apply style $ ("# myid"). addclass ("myclass") delete style $ ("# myid"). removeclass ("myclass ")
Add a sample (##myid=).css ("height", “20px1_ ((((##myid=).css ({Height: "20px", width: "100px"}). Note that if you add a style, the name of this style is the name in CSS, for example, style = "background-color: # ff0000". The corresponding jquerywrite method is (((#myid=).css ("background-color", "# ff0000 ″) however, when adding a set of styles, the style name is the CSS name in Javascript, for example, myid. style. backgroundcolor = "# ff0000". The corresponding jquerywrite method is certificate ({{myid=}.css ({backgroundcolor: "# ff0000 ″})

4. find the next element at the same level as the link $ ("# myid "). next () Find all the elements in the same level as yourself $ ("# myid "). nextall () finds the last element at the same level as itself $ ("# myid "). prev () searches for all elements on top of itself at the same level as itself $ ("# myid "). prevall () find your first child element $ ("# myid "). children () find your first parent element $ ("# myid "). parent () finds all its parent elements $ ("# myid "). parents () Example: $ ("Div. l4 ″). parents (). each (function () implements alert((this).html ());});
All the parent elements of the class = L4 Div are obtained, and alert outputs their html
Example: $ ("Div. l4 ″). parents ("Div. l2 ″). each (function () {alert(((this).html () ;}); the parent element of class = L4 is obtained. The parent element must be a div and its class = L2
All the methods mentioned here can contain expressions. For the expression writing method, refer to the first part.

5. add an element to the body $ ("body "). append ("<input type = 'text' value = 'asd '/>") This statement inserts the HTML into the end tag of the body, the result is <input type = 'text' value = 'asd '/> </body>
$ ("Body "). prepend ("<input type = 'text' value = 'asd '/>") This statement inserts the HTML into the start tag of the body, the result is <body> <input type = 'text' value = 'asd '/>

6. ajax uses the get method to request a page $. get ("http://www.google.com", "q = jquery", function (data, status) {alert (data)}) indicates the request http://www.google.com, the parameter is Q, the parameter value is jquery, after a request is completed (whether successful or failed), the function has two fixed parameters: Data and status. Data is the returned data and status is the status of the request.
Use the POST method to request a page $. Post (........) The parameter is the same as the get method.

7. Other Methods $. Trim (STR) Remove spaces before and after STR $. browser returns the type of the current user's browser $. browser. Version returns the version of the current Browser
8. Plug-ins jquery support plug-ins, http://jquery.com/plugins/ there are a lot of plug-ins, you can also write your own plug-ins, please refer to the http://docs.jquery.com/Core/jQ.....end#object and http://docs.jquery.com/Core/jQuery.extend#object

1. drop-down box: var PC3 =$ (". formc select [@ name = 'country'] Option [@ selected] "). text (); // get the text of the selected item in the drop-down menu (note that there is a space in the middle) var CC2 = $ ('. formc select [@ name = "country"] '). val (); // obtain the value of the selected item from the drop-down menu var CC3 = $ ('. formc select [@ name = "country"] '). ATTR ("ID"); // get the ID attribute value of the selected item from the drop-down menu $ ("# select "). empty (); // clear the drop-down box // $ ("# select" example .html (''); $ ("<option value = '1'> 1111 </option> "). appendto ("# select") // Add the option in the drop-down box to explain a little: 1. select [@ name = 'country'] O Ption [@ selected] indicates the option element with the selected attribute in the select element with the name attribute and the attribute value of 'country; it can be seen that the attribute is followed by the @ parameter.

2, single sector: $ ("input [@ type = radio] [@ checked]"). val (); // get the value of the selected item of a single sequence (note that there is no space in the middle) $ ("input [@ type = radio] [@ value = 2]"). ATTR ("checked", 'checked'); // set single checked value = 2 to the selected status. (Note that there is no space in the middle)

3. Check box: $ ("input [@ type = checkbox] [@ checked]"). val (); // obtain the value of the first check box $ ("input [@ type = checkbox] [@ checked]"). each (function () {// Since multiple check boxes are selected, You can output alert ($ (this) cyclically ). val ());});
$ ("# CHK1 "). ATTR ("checked", ''); // do not tick $ (" # CHK2 "). ATTR ("checked", true); // tick if ($ ("# CHK1 "). ATTR ('checked') = undefined) {} // checks whether the check has been completed.