JQueryselect operation control method summary _ jquery

Many of my friends are very interested in jqueryselect operations, but there are too many things on the Internet. Therefore, I specially sorted out the JquerySelect operation methods for your convenience. Note that many of the code here is for versions earlier than jquery 1.32 (@ is not supported in later versions), so replace it with an empty test.

JQuery gets the selected Text and Value of Select:
Syntax explanation:
1. $ ("# select_id"). change (function () {// code...}); // Add an event for Select, triggered when one of the Select events is selected
2. var checkText = $ ("# select_id"). find ("option: selected"). text (); // obtain the selected Text
3. var checkValue = $ ("# select_id"). val (); // obtain the Value selected by Select
4. var checkIndex = $ ("# select_id"). get (0). selectedIndex; // obtain the index value selected by Select

5. var maxIndex = $ ("# select_id option: last"). attr ("index"); // obtain the largest index value of Select.

JQuery sets the Text and Value selected by Select:
Syntax explanation:
1. $ ("# select_id"). get (0). selectedIndex = 1; // Select an item whose Select index value is 1
2. $ ("# select_id"). val (4); // Select an item whose Value is set to 4.
3. $ ("# select_id option [text = 'jquery ']"). attr ("selected", true); // set the Select Text value to jQuery.


JQuery adds/deletes Select Option items:
Syntax explanation:
1. $ ("# select_id"). append (" Text"); // Append an Option to Select (drop-down)
2. $ ("# select_id"). prepend (" Select"); // Insert an Option for Select (first position)
3. $ ("# select_id option: last"). remove (); // Delete the largest Option (last) index value in Select)
4. $ ("# select_id option [index = '0']"). remove (); // Delete the Option with the index value 0 in Select (the first option)
5. $ ("# select_id option [value = '3']"). remove (); // Delete the Option with Value = '3' In the Select statement
5. $ ("# select_id option [text = '4']"). remove (); // Delete the Option of '4' Text = '4' in Select


// Traverse option and add or remove option
Function changeShipMethod (shipping ){
Var len = $ ("select [@ name = ISHIPTYPE] option"). length
If (shipping. value! = "CA "){
$ ("Select [@ name = ISHIPTYPE] option"). each (function (){
If ($ (this). val () = 111 ){
$ (This). remove ();
}
});
} Else {
$ (" UPS Ground"). AppendTo ($ (" select [@ name = ISHIPTYPE] ");
}
}


// Obtain the selected value from the drop-down list

$ (# TestSelect option: selected'). text ();
Or $ ("# testSelect"). find ('option: selected'). text ();
Or $ ("# testSelect"). val ();
//////////////////////////////////////// //////////////////////////
If your memory is poor, you can add it to your favorites:
1. drop-down box:

Var C0 = $ (". formc select [@ name = 'country'] option [@ selected] "). text (); // get the text of the selected item from 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"); // obtain the ID attribute value of the selected item from the drop-down menu
$ ("# Select"). empty (); // clear the drop-down box // $ ("# select" example .html ('');
$ (" 1111"). AppendTo (" # select ") // Add the option in the drop-down box

A little explanation:
1. select [@ name = 'country'] option [@ selected] indicates that the name attribute exists,
In addition, the select element with the selected attribute in the 'country' select element has the selected attribute;
It can be seen that the attribute is followed by the @ parameter.

2, single region:
$ ("Input [@ type = radio] [@ checked]"). val (); // obtain 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 them cyclically.
Alert ($ (this). val ());
});

$ ("# Chk1"). attr ("checked", ''); // do not check
$ ("# Chk2"). attr ("checked", true); // check
If ($ ("# chk1"). attr ('checked') = undefined) {}// you can check whether a check has been performed.


Of course, jquery's selector is powerful. There are many other methods.