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HomeWeb Front-endJS TutorialSummary of knowledge points about Selector in jQuery

Summary of knowledge points about Selector in jQuery

Jun 21, 2017 am 09:45 AM
jqueryselectorSummaryKnowledge pointsSelector

jQuery Selector Summary, friends in need can refer to it, they are some commonly used selection control methods.

//jQuery selector$
//$(expression,[context]) return jQuery
//Unit One
//The CSS definer of expression is to express the element to be selected in CSS syntax

// $("*"); // Represents all element tags on the page
// $("th, td") // Represents all

element tags
// $("a") // Represents all element tags
// $("p#onlyp"); // Represents elements with id=onlyidv in CSS selection $("#ID ") matches the entire document
// $("#rating"); // Represents elements with id=rating
// $("#orderedlist > li"); // Represents all elements with id=orderedlist Child elements, but not including child elements under the child element
// $("#orderedlist li:last"); // Represents the last element of li in id=orderedlist
// $("#orderedlist li :first"); //Represents the first element of li in id=orderedlist
// $("#orderedlist li:nth- child(0)"); //Represents the (N) element of li in id=orderedlist The element n is the array subscript
// $("button:only-child"); //Indicates that it is the only element of the parent container in the css selection
// $(".stuff:empty" ); // Represents empty elements in css selection
// $(".buttons:enabled"); // Represents normally enabled elements in css selection
// $(".buttons:disabled" ); // Represents non-enabled elements in css selection
// $("input:checked"); // Represents selected elements in css selection
// $("button:not(.not )"); // Indicates the removal of elements in not() in css selection
// $("button.not"); // Indicates the elements with class=not in css selection $(".CLSS" ) matches the entire document
// $("#orderedlist2 li"); // Indicates all sub-elements of id=orderedlist and includes the sub-elements of all sub-elements
// //alert($("#orderedlist ~ li").length);
// $("#orderedlist,.buttons,li"); //Elements matching css selector



//expression of Select based on element attributes
// alert($("button[@class]").length); // Indicates elements with class attributes
// alert($("button[@class=not" ).length); // Indicates an element with a class attribute and a value equal to not
// alert($('button[@class^=not').length); // Indicates an element with a class attribute and a matching value at the beginning Elements of not
// alert($('button[@class$=not').length); // Indicates elements with class attributes and the end of the value matching not
// alert($('button [@class*=not').length); // Indicates elements with class attributes and values ​​that match not
//expression of XPATH
Filter XPATH syntax to indicate the page elements that need to be selected
//$("ol[@id^='orderedlist']").find("li:contains('First')").each(function(i) {
//// $ (this).html( $(this).html() + " BAM! " + i );
// $(this).mouseover(function(){
// $(this).css ("color","red");
// });
// $(this).mouseout(function(){
// $(this).css("color", "#000");
// });
// });
//Find all elements with the ol tag and the attribute id=orderedlist, there are two ways to write it
//ol [@id='orderedlist'] To locate the parent element, directly use each iteration
//ol[@id='orderedlist']/* For all child elements under the parent element, use find('child- element').each( )Iteration

//Unit two
///$(html, [ownerDocument]) return jQuery
//This function allows passing in html elements text, constructor A jQuery object created by this HTML text will be generated. This object may not exist originally, or it may exist on the original page.
//$('

hello

').appendTo("h2 "); //Generate a markup text and append it to the h2 tag of the page
//You can also take out the original page element and append it
//$("input",this).appendTo("h2"); //Note that the page elements taken out here are moved! Not copied

///$(elements) return jQuery
//This function allows direct passing into the DOM
//$( document.forms[0].elements).appendTo("h2"); // You can refer to the DOM document
//$(callback) return jQuery



//The following is Some instructions for selector
/*
Basics:

#id: Get the object based on its id attribute.
element: All objects that match a certain HTML tag
.class: Get the object according to the class attribute of the object
*: Get all the objects
selector1, selector2, selectorN: Get a collection of multiple selectors without removing duplicates

Hierarchical selectors:
ancestor descendant: This selector is a space, which means that all objects of the first selector are found first, and then Find all objects that match the second selector among the descendant nodes of .
parent > child: This selector is the greater than sign, which means to first find all the objects of the first selector, and then find all the objects that match the second selector in its child nodes (not grand children). .
prev + next: This selector is the plus sign, which means to first find all the objects of the first selector, and then find the objects that follow the next node of the same level and also match the second selector.
prev ~siblings: This selector is the ~ sign, which means to first find all objects of the first selector, and then find objects that match the second selector in all subsequent nodes at the same level.

Basic filter characters:
:first: Match the first object among multiple objects
:last: Match the last object among multiple objects
:not(selector): Matches items with the content in the selector after not removed
:even: matches the even number among all objects
:odd: matches the odd number among all objects
:eq(index): matches a certain A single element in the following table
:gt(index): Matches all elements greater than a certain subscript
:lt(index): Matches all elements less than a certain subscript
:header: Matches all header elements, For example, h1, h2, h3, h4, h5, h6
:animated: Match all elements with animated effects

Text filter:
:contains(text): Match the text element that has the internal content Objects, including indirect useful situations
:empty: match all objects without child elements
:has(selector): match all objects that contain at least one child selector
:parent: match all parents Object, the parent object contains those objects that only contain text

Visibility filter:
:hidden: matches all hidden objects, or the hidden type in the input
:visible: matches all visible objects

Attribute filter:
[attribute]: Matches all objects with a certain attribute
[attribute=value]: Matches objects with a certain attribute and value
[attribute!= value]: Match objects that have a certain attribute and are not a certain value
[attribute^=value]: Match objects that have a certain attribute and start with a certain value
[attribute$=value]: Match objects that have a certain attribute and end with a certain value
[attribute*=value]: Match objects that have a certain attribute and contain a certain value
[selector1] [selector2][selectorN]: Match objects that match multiple attribute selectors at the same time

Child filter:
:nth- child(index/even/odd/equation): Match a certain subscript/even/odd/ in the child element For equation objects, :eq(index) can only match the characteristics of a child element of a single object, while this method can match the common characteristics of a certain child element of multiple objects
:first-child: Match the first child element
:last- child: Match the last child element
These two matchers can also match all child elements of multiple parent objects
:only-child: If If a parent element has only one child element, it will match this child element

Form filter character
Name Type

:input Returns: Array
Matching form Inner input element

:text Returns: Array
Match elements whose input type is text in the form

:password Returns: ArrayMatch elements in the form whose input type is password

:radio Returns: Array
Match elements in the form whose input type is radio

: checkbox Returns: Array
Match elements whose input type is checkbox in the form

:submit Returns: Array
Match the input type in the form is Submit elements

:image Returns: Array
Elements that match the image in the form

:reset Returns: Array
Match elements in the form whose input type is reset

:button Returns: Array
Match elements in the form whose input type is button

:file Returns: Array
Match elements whose input type is file in the form.

:hidden Returns: Array
Match elements whose input type is hidden in the form Element or hidden area



:enabled Returns: Array
Match all enabled elements

:disabled Returns: Array
Match all non-enabled elements

:checked Returns: Array
Match all selected elements

:selected Returns: Array
Match allDrop-down listSelected element

*/

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