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Understanding HTML languages
Web developers think that HTML is the most trivial technology, but it is the foundation; Hypertext Markup Language extension can be:. html or. htm;<>: start tag; </>: end tag; tags can also be called containers ; Individual labels can be used alone, such as <br>;
The concept of elements and labels need not be strictly differentiated;
Property values can be either in quotation marks or in quotation marks, and can be double quotes or single quotes, and some attributes have only two optional values, you do not have to write property values, you write a property name to represent a true value, and do not write false;
not sensitive to case;
The way the browser opens a Web page document: It can be opened locally or open from a Web browser; HTML tags tell the browser how to display text, HTML is a markup language rather than a programming language, it only shows logic without business logic; HTML specification and version:
Incompatibility issues between different browsers: Some designers have special effects for their browsers, then design special tags that can be used in their own browsers to become the dialect of HTML tags, while other browsers do not know such dialects, so we define the specification; As demand changes, New specifications are being introduced; the IETF has given permission to define HTML specifications to the consortium; the HTML version in use: html4.01, the final specification, because XHTML will replace HTML;
IETF and the consortium:
If you want to sell socket, you must know the specification, otherwise your socket other people can not use; Ietf:internet Engineering task force,internet project team;
www.ietf.org;
In RFC naming various standards, Requests for comments, request the annotation document;
For example: RFC2616 (http/1.1), RFC1521 (MIME);
An RFC document must be assigned a number, and a coded RFC document cannot be updated;
IETF revenue: Manufacturers that are manufactured according to standards must pay the IETF for the purchase criteria;
W3c:world Wide Web consortium,www Alliance;
www.w3c.org;
Any company can join;
Does not have legal effect;
Global schema label for HTML
The contents of the The properties of the <body bgcolor=red text=blue>body tag set the global page properties;
Properties of <body>:
Text: The color of the entire page;
Link: The text color of the hyper-connection;
ALink: The color of the text when the mouse moves to the super connection;
Vlink: Sets the text color of the hyperlink you have visited;
Background: background image; it's because the body is global, so this picture
is not like image images, is the overall background;
You're lazy, though you don't always use quotes, but when you're using a link address, like writing a
Hyperlink or the path of a picture, it is necessary to write quotes;
Bgcolor:background will flush out the effect of this property;
Leftmagin/topmargin: Web page display screen and the left/top margin of the browser;
Class,name,id,style and other public properties;
There are two ways to represent colors:
#XX xx xx Three two-bit hexadecimal data, with just 8 digits per two digits representing 256 levels of
Red, green and blue;
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 transitional//en" >
This is the document type definition statement, which is the specification of the HTML document;
DTD syntax: <! DOCTYPE HTML Public "version name" "URL" >
DOCTYPE Specify document type: HTML
Public: to indicate that it is publicly accessible, rather than an internal document of a company;
Version name specifies the edition of the document;
The URL specifies the location of the specification file on the Internet;
Do not relate the file extension to the DOCTYPE in the document type definition, in fact the two
It doesn't matter, you can find an. xml file is not a definition of XML at all, but a deployment descriptor for Web applications;
Notes with special characters
<!--annotation-->
Although the browser does not display the annotation content, but view the original file can still see the annotation;
If you want to make the label as normal text display, or want to display multiple spaces correctly, you need to use:< instead of < > Replace >; instead of spaces; this notation is called HTML encoding: Start with &; To display characters that cannot be entered by the keyboard, such as the copyright symbol, for simplicity, you can use the language to spell, for example, © can replace the digital representation of the copyright symbol;
Common:& & < < > >
"" A circle in a R
© a TM in the upper right corner of a c™ in a circle
Why use " to say "?
Property =a B or attribute = "a" B "the browser only thinks the property value is a;
In short, the browser starts with the first quotation mark and encounters the next same quotation mark as
property value;
A property value that has both single and double quotes can cause serious ambiguity.
So you can use " to prevent browsers from prematurely putting a "thought" as the end of a property value;
Why are you coding for &?
It's very simple, all coding is used to start with &, when I want to use & as ordinary characters
There must be a problem; this is the same as the problem with% and _ in SQL;
Format labels
<P> attribute Align=right/left;
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