day36
Reprinted from https://www.cnblogs.com/majj/category/1218953.html
html
! Html plus tab key will follow complements
-
w3c: World Wide Web Consortium organization, used to develop web standards bodies (organizations)
-
web standards: web pages follow norms
-
web prepared formal classification: structural standards, performance standards, standards of conduct.
-
Structure: html. He represents: css. Behavior: Javascript.
web Preparation summary:
-
Standard Structure: equivalent to the human skeleton. html is used to create web pages.
-
Performance Standards: the equivalent of their clothing. css is the beautification of the web pages.
-
Standards of conduct: the equivalent of human action. JS is to make web pages move, with vitality
PS: "browser kernel" that is used by the browser "rendering engine", the browser rendering engine determines the format of the information content of the page and how to display the page.
Summary: The rendering engine is the root cause compatibility problems.
html stands for HyperText Mackeup Language, translated into HTML, it is not a programming language, is a descriptive markup language for describing display hypertext content. Such as font, color, size and so on.
-
Hypertext: audio, video, pictures, called hypertext.
-
Tag: <English words or letters> called tag, an HTML page is composed from a variety of markers.
Role: HTML is responsible for describing the semantics of the document language.
Note: HTML is not a programming language language (there are compilation process), but a markup language (no compilation), HTML pages directly from the browser parse executed.
HTML is responsible for describing the semantics of the language of the document, in html, in addition to semantics, nothing else.
This article is a pure html file (txt file is to use the renamed made), with some tags to describe the semantics of the text, these tags in the browser which is not visible, so called "hypertext", so is the "hypertext Markup language "was.
2, HTML web term
-
Pages: a page composed of various marks called pages.
-
Home (Home): a website start page or navigation page.
-
Tag: <p> called the start tag, </ p> end tag is called, also called tags. Each tag ordained a special meaning.
-
Element: <p> SUMMARY </ p> called elements.
-
Properties: to each label made auxiliary information
HTML color presentation
1. color representation
-
Pure word representation: red, green, blue, orange, gray, etc.
-
10 hexadecimal: rgb (255,0,0)
-
Hexadecimal: # FF0000, # 0000FF, # 00FF00 etc.
2.RGB color mode
1. color representation
-
Pure word representation: red, green, blue, orange, gray, etc.
-
10 hexadecimal: rgb (255,0,0)
-
Hexadecimal: # FF0000, # 0000FF, # 00FF00 etc.
2.RGB color mode
-
Nature of all the colors can be red, green, blue (RGB) intensity of the three different colors obtained by a combination of wavelengths, which is commonly known as the principle of the three primary colors.
-
RGB RGB is also called additive color model, because when we put different wavelengths of light are added together, they can get a different mixed colors. Example: Yellow = Red + Green, Red + Blue = violet, green and blue = green +
-
In digital video, the three primary colors of RGB each 8-bit encoding constitutes approximately 16.78 million kinds of color, this is what we often say that the true color. All display devices are used in a RGB color mode.
-
Each RGB 256 (0-255) brightness, RGB color 256 of total composition of about 16.78 million kinds of colors, i.e., 256 × 256 × 256 = 16777216.
Six, HTML specification
-
HTML is a weak language
-
HTML is not case sensitive
-
Extension of the HTML page is html or htm (some systems do not support extension longer than three characters, such as dos system)
-
HTML structure:
-
Declarations section: The main role is to tell the browser to use this page Which standards. HTML5 is standard.
-
head part: some extra information page tells the server. It will not be displayed on the page.
-
body parts: we have written code must be placed within this tag.
1, specification writing HTML
1) All the elements must be properly nested tag, you can not cross nested. Example correct wording: <h1> <font> </ font> </ h1>
(2) All tags must be lowercase.
(3) All tags must be closed.
-
Bilateral tag: <span> </ span>
-
Unilateral mark: <br> turn into <br /> <hr> converted to <hr />, as well as <img src = "URL" />
(4) all attribute values must be quoted. <H1 id = "head"> </ h1>
(5) All property must have a value. <Input type = "radio" checked = "checked" />
2, the basic grammatical features of HTML
-
HTML is not sensitive to wrap insensitive to tab
Only care about HTML tags nested structure of nested relations. Who nested whom, who nested whom, and line breaks, tab unrelated. For no change line, tab not tab, does not affect the structure of the page.
In other words, HTML instead of relying indentation to represent nested, it is to see the relationship between the package label. However, we have found a good indentation, code more readable. He asked us to correctly indent tag.
-
Blank folding phenomenon
Among all the HTML text, if there are spaces, line breaks, tab will be folded into a blank display.
-
The label should be strictly closed
1, the first document declaration
Any standard HTML page, the first line is a must in order to
<!DOCTYPE...
The beginning of the line, is the first document declaration, DocType Declaration, referred to as the DTD. This tag tells the browser which HTML or XHTML specification documentation use.
XHTML: Extensible Hypertext Markup Language, Extensible Hypertext Markup Language.
The main purpose of XHTML is to replace HTML, it can be understood as an upgraded version of HTML.
HTML tags writing is not standardized, it will cause other devices (ipad, phone, TV, etc.) can not be displayed properly.
XHTML markup HTML4.0 with substantially the same.
XHTML is strict, pure HTML
2, the first label (head)
head tag are placed between the head portion. It contains the: <title>, <meta>, <link>, <style>
-
<Title>: Specifies the entire page title is displayed at the top of the browser.
-
<Meta>: provide basic information about the page
-
<Link>: define the relationship between a document and an external resource.
-
<Style>: define the relationship between internal style sheet to a web page
Meta Tags
Elements can provide information on the original page (mata-information), and description for search engines update frequency and keyword.
Label is located on top of the document does not contain any content.
Information provided by the user is not visible. Consisting of meta tags: meta tag has two attributes, they are http-equiv and name attributes, different attributes have different parameter values, these different parameter values to achieve a different page functions.
Common meta tags:
-
http-equiv attribute
It is used to convey useful information to the browser help browser correctly displays Web page content, the corresponding attribute value content, the content is actually the content of the variables of each parameter value.
<! - 2 seconds after the jump to the corresponding redirection URL, attention semicolon ->
<meta http-equiv="refresh" content="2;URL=
http://www.luffycity.com">
<! - content type and encoding type specified document ->
<meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
<! - tell the IE browser to render the current most advanced mode page ->
<meta http-equiv="x-ua-compatible" content="IE=edge">
-
The name attribute
Mainly for the keywords and description of the page, the search engine is written to see, there may be a plurality of keywords with ',' number of spaced, content attribute values corresponding thereto, the content of the main content is to facilitate the search engine robot find information and use of classified information.
<Meta name = "Keywords" content = "Netease, email, games, news, sports, entertainment, female, Asian Games, forums, SMS" />
These keywords is to tell the search engine, the website is doing, can improve search hits. So that others can find you, search.
<Meta name = "Description" content = "NetEase is China's leading Internet technology company, to provide users with free e-mail, games, search engine services, the creation of news, more than 30 content channels and entertainment, sports, and blog, videos, forum and other interactive exchanges, Wang Ju people power. "/>
Just set Description page description, then the Baidu search results can be displayed these statements, this technique is called SEO (search engine optimization, search engine optimization).
<meta name=viewport content="width=device-width, initial-scale=1">
Above this label, it is to make our website supports mobile terminal, mobile device priority (to understand)
title tags
What are the main mainly used to tell users and search engines This page is a search engine page title can quickly determine the theme of the current page.