Official JQuery website

Official JQuery website
Basic knowledge

JQuery is JavaScript and Query, which is the library that assists JavaScript development.

The file types are divided into the full version and compiled

Use: Create a folder in the file, copy the JQuery package to the folder, and reference

$ Is a special symbol of JQuery that must be written.

Selector

Example:

<Div id = "div1" class = "div1">

<A> aaaaaaaaaaaa </a>

</Div>

<Div class = "div"> </div>

<Div id = "div2"> </div>

Basic Selector

ID selector: $ ("# div1 ")

Class selector: $ ("div ")

Tag Selector 

Parallel: Use commas to separate $ ("# div1, # div2" labels can be appended with .css (style) 

Descendant: separated by Spaces

Filter Selector

Basic Filter

Beginning and end

$ (". Div: first/last ")

Any

Eq (Index Number) $ (". div: eq ()")

Not equal

Greater

: Gt ();$ (". Div: gt ()")

Less

: Lt ();$ (". Div: lt ()")

Exclude

$ (". Div: not (. div: eq (index number ))")

Parity

$ (". Div: odd/even ")

Attribute name Filtering

$ (". Div [attribute name]")

Content Filtering

Text $ (". div: contains (" string ")")

Child element $ (". div: has (selector )")

Event

Regular events

1. Remove onclick on from js.

Format:

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

}); (Double-click dblclick)

Composite event

$ (". Div"). hover (function (){

Certificate (this).css ("background-color", "red ");

}, Function (){

Certificate (this).css ("background-color", "white ");

}); (BEAM)

$ (". Div"). toggle (function (){

Certificate (this).css ("background-color", "red ");

},Function (){

Certificate (this).css ("background-color", "green ");

},Function (){

((This).css ("background-color", "yellow ");

},Function (){

Certificate (this).css ("background-color", "gray ");

}); (Click to switch continuously)

Event bubbling

Blocking time bubbling:

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

Return false;

})

DOM operations

Operation content (change content)

$ ("# A"). click (function (){

$ (This). text ("bbbb ");

});

Content Changes in the text box

$ ("# Button"). click (function (){

$ ("# Text box"). val ("changed content ");

$ (This). val ("button changed content ");

})

Add

$ (Document). ready (function (){

Write internally

})

Operation content

Form Element

Value: var s = $ ("selector"). val ()

Value assignment: $ ("selector"). val ("value ")

Non-form Element

Value: var s = $ ("selector" ).html (), var s = $ ("selector"). text ()

Value assignment: $ ("selector" ).html ("content"), $ ("selector"). text ("content ")

Operation attribute

Get attributes: var s = $ ("selector"). attr ("attribute name ")

Set attributes: $ ("selector"). attr ("attribute name", "attribute value ")

Delete attribute: $ ("selector"). removeAttr ("attribute name ")

Operation Style

Operation inline Style

Get style: var s = $ ("selector" ).css ("style name ")

Set style: $ ("selector" ).css ("style name", "value ")

Operate the css of a style sheet

Add class: $ ("selector"). addClass ("class Name ")

Remove class: $ ("selector"). removeClass ("class Name ") 

Add and remove alternate class: $ ("selector"). toggleClass ("class Name ")

 Operation-related elements

Example: <style type = "text/css">

# Div1 {

Width: 400px;

Height: 400px;

Background-color: red;

}

# Div2 {

Width: 300px;

Height: 300px;

Background-color: blue;

}

# Div3 {

Width: 200px;

Height: 200px;

Background-color: yellow;

}

<Div id = "div1">

<Div id = "div2">

<Div id = "div3">

</Div>

</Div>

</Div>

 

Search

Parent and predecessors

$ ("Div3"). click (function (){

Var a = $ (this). parent ();

}); (Previous)

Adding. parent after parent is the first level.

$ ("Div3"). click (function (){

 Var a = $ (this). parents ("# div1 "); 

}); (Predecessors)

Child and younger generation 

$ ("Div1"). click (function (){

 Var a = $ (this). children (); (sub) 

});

$ ("Div1"). click (function (){ 

Var a = $ (this). find ("# div3 ");(Younger generation)

});

Example:

<Div id = "div1"> </div>

<Div id = "div2"> </div>

<Div id = "div3"> </div>

Brother

Next is followed by an element nextAll (all) (selector) followed by a sibling element.

Prev prevAll (all) (selector)

 $ ("Div1"). click (function (){ 

 Var a = $ (this). next (). next (); 

 });

Operation

New

$ ("HTML string ")

Add

(1) appen (jquery object) add (2) after (,...) lower level add (3) before ("...")Add upper level

Copy

Clone ()

Remove

(1) empty () Clear all internal elements (2) remove () remove elements