CSS Selectors

16 ก.ย. 2019 , 1,802 Views   , หมวดหมู่ WebDesign โค๊ดดิ้ง   , ป้ายกำกับ:,


แบ่งออกเป็น 5 ประเภท

Simple selectors

Element Selector

ตัวอย่าง

ID Selector (#)

ID ในหนึ่งหน้ามี ID เดียว

ตัวอย่าง

Class Selector (.)

ในหนึ่งหน้า สามารถมีได้หลาย Class

ตัวอย่าง

ระบุ Element ที่มี Class ที่ต้องการ

Element นึงมีได้หลาย Class

 

All CSS Simple Selectors

Selector Example Example description
.class .intro Selects all elements with class=”intro”
#id #firstname Selects the element with id=”firstname”
* * Selects all elements
element p Selects all <p> elements
element,element,.. div, p Selects all <div> elements and all <p> elements

Combinator Selectors ความสัมพันธ์ระหว่าง Selector

Selector Example Example description
elementelement div p Selects all <p> elements inside <div> elements
element>element div > p Selects all <p> elements where the parent is a <div> element
element+element div + p Selects all <p> elements that are placed immediately after <div> elements
element1~element2 p ~ ul Selects every <ul> element that are preceded by a <p> element

CSS Pseudo-classes

A pseudo-class is used to define a special state of an element.

For example, it can be used to:

  • Style an element when a user mouses over it
  • Style visited and unvisited links differently
  • Style an element when it gets focus

All CSS Pseudo Classes

Selector Example Example description
:active a:active Selects the active link
:checked input:checked Selects every checked <input> element
:disabled input:disabled Selects every disabled <input> element
:empty p:empty Selects every <p> element that has no children
:enabled input:enabled Selects every enabled <input> element
:first-child p:first-child Selects every <p> elements that is the first child of its parent
:first-of-type p:first-of-type Selects every <p> element that is the first <p> element of its parent
:focus input:focus Selects the <input> element that has focus
:hover a:hover Selects links on mouse over
:in-range input:in-range Selects <input> elements with a value within a specified range
:invalid input:invalid Selects all <input> elements with an invalid value
:lang(language) p:lang(it) Selects every <p> element with a lang attribute value starting with “it”
:last-child p:last-child Selects every <p> elements that is the last child of its parent
:last-of-type p:last-of-type Selects every <p> element that is the last <p> element of its parent
:link a:link Selects all unvisited links
:not(selector) :not(p) Selects every element that is not a <p> element
:nth-child(n) p:nth-child(2) Selects every <p> element that is the second child of its parent
:nth-last-child(n) p:nth-last-child(2) Selects every <p> element that is the second child of its parent, counting from the last child
:nth-last-of-type(n) p:nth-last-of-type(2) Selects every <p> element that is the second <p> element of its parent, counting from the last child
:nth-of-type(n) p:nth-of-type(2) Selects every <p> element that is the second <p> element of its parent
:only-of-type p:only-of-type Selects every <p> element that is the only <p> element of its parent
:only-child p:only-child Selects every <p> element that is the only child of its parent
:optional input:optional Selects <input> elements with no “required” attribute
:out-of-range input:out-of-range Selects <input> elements with a value outside a specified range
:read-only input:read-only Selects <input> elements with a “readonly” attribute specified
:read-write input:read-write Selects <input> elements with no “readonly” attribute
:required input:required Selects <input> elements with a “required” attribute specified
:root root Selects the document’s root element
:target #news:target Selects the current active #news element (clicked on a URL containing that anchor name)
:valid input:valid Selects all <input> elements with a valid value
:visited a:visited Selects all visited links

All CSS Pseudo Elements

Selector Example Example description
::after p::after Insert content after every <p> element
::before p::before Insert content before every <p> element
::first-letter p::first-letter Selects the first letter of every <p> element
::first-line p::first-line Selects the first line of every <p> element
::selection p::selection Selects the portion of an element that is selected by a user

CSS Attribute Selectors

All CSS Attribute Selectors

Selector Example Example description
[attribute] [target] Selects all elements with a target attribute
[attribute=value] [target=_blank] Selects all elements with target=”_blank”
[attribute~=value] [title~=flower] Selects all elements with a title attribute containing the word “flower”
[attribute|=value] [lang|=en] Selects all elements with a lang attribute value starting with “en”
[attribute^=value] a[href^=”https”] Selects every <a> element whose href attribute value begins with “https”
[attribute$=value] a[href$=”.pdf”] Selects every <a> element whose href attribute value ends with “.pdf”
[attribute*=value] a[href*=”w3schools”] Selects every <a> element whose href attribute value contains the substring “w3schools”

 

ดูเพิ่มเติม : https://www.w3schools.com/css/css_selectors.asp


ป้ายกำกับ:,