Detailed explanation of HTML hyperlinks_HTML/Xhtml_Web page production

Hyperlink

Hyperlink is a frequently used HTML element in websites, because various pages of the website are connected by hyperlinks, and hyperlinks complete the jump between pages. Hyperlinks are the main means of interaction between browsers and servers, and we will gradually learn more about them in the following technologies.

— Note: Pictures can also be used as links. You will learn more about them in the next chapter "Pictures in Web Pages".

4.5.1 Add link to text

The tag of a hyperlink is . Adding a hyperlink to text is similar to other modification tags. The text after adding the link has its own special style to distinguish it from other text. The default link style is blue text with underline. A hyperlink jumps to another page. The tag has an href attribute responsible for specifying the address of the new page. The address specified by href generally uses a relative address.

— Note: In website development, document relative addresses are more commonly used.

Create a web page file in the D:web directory, name it a.htm, and write the code as shown in Code 4.18.

Code 4.18 Hyperlink settings: a.htm

Enter the list settings page

Enter http://localhost/a.htm in the browser address bar, and the browsing effect is as shown in Figure 4.19.

Figure 4.19 Hyperlink settings

Readers can see the default style of hyperlinks in Figure 4.19. When clicking the link on the page, the page will jump to the ul_ol.htm page in the same directory, which is the list setting page in the previous section. When you click the browser's "Back" button to return to the a.htm page, the color of the text link turns purple to tell the viewer that this link has been visited.

4.5.2 Modify the link window opening method

By default, hyperlinks open new pages by overwriting themselves. According to the different needs of the browser, the reader can specify other ways of opening a new window for the hyperlink. The hyperlink tag provides the target attribute for setting. The values ​​are _self (self-overwriting, default), _blank (create a new window to open a new page), _top (open in the entire window of the browser, all frame structures will be ignored) ), _parent (open in the previous window).

— Note: The _top and _parent methods are used for frame pages, and will be explained in detail in later chapters.

4.5.3 Add prompt text to the link

In many cases, the text of the hyperlink is not enough to describe the content to be linked. The hyperlink tag provides the title attribute to conveniently give prompts to the viewer. The value of the title attribute is the prompt content. When the viewer's cursor stays on the hyperlink, the prompt content will appear. This will not affect the neatness of the page layout. Modify the a.htm web page file and write the code as shown in code 4.19.

Code 4.19 Hyperlink settings: a.htm

Enter the list settings page

Enter http://localhost/a.htm in the browser address bar, and the browsing effect is as shown in Figure 4.20.

Figure 4.20 Hyperlink prompt text

4.5.4 What is an anchor

Many web articles have a lot of content, resulting in very long pages, and viewers need to constantly drag the browser's scroll bar to find the content they need. The anchor function of the hyperlink can solve this problem. The anchor is derived from the anchor on the ship. After the anchor is dropped, the ship will not easily drift away or get lost. In fact, anchors are used to jump to different locations within a single page. Some places are called bookmarks.

The name attribute of the hyperlink tag is used to define the name of the anchor. A page can define multiple anchors. The href attribute of the hyperlink can jump to the corresponding anchor based on the name. Create a web page file in the D:web directory, name it a_anchor.htm, and write the code as shown in Code 4.20.

Code 4.20 Hyperlink anchor: a_anchor.htm

Here is the top anchor

1st

2nd

3rd term

The 4th

The 5th

The 6th

Presidents of the United States

●1st term (1789-1797)This is the anchor of the 1st term

Name: George Washington

George Washington

Birth and death: 1732-1799

Political Party:: Federation

●The 2nd term (1797-1801)This is the anchor of the 2nd term

Name: John Adams

John Adams

Birth and death: 1735-1826

Political Party:: Federation

●The 3rd term (1801-1809)This is the anchor of the 3rd term

Name: Thomas Jefferson

Thomas Jefferson

Birth and death: 1743-1826

Political party:: Communist Party of China

●The 4th (1809-1817)This is the anchor of the 4th

Name: James Madison

James Madison

Birth and death: 1751-1836

Political party: Democratic Republic of China

●The 5th (1817-1825)This is the anchor of the 5th

Name: James Monroe

James Monroe

Birth and death: 1758-1831

Political party: Democratic Republic of China

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Before testing, readers can see from code 4.20 that the tag is also used to define anchors, and the name of the anchor is defined with the name attribute (the name has no limit and can be customized). When looking for anchor links, use the href attribute to specify the corresponding name, and add a # symbol in front of the name. Enter http://localhost/a_anchor.htm in the browser address bar, and the browsing effect is as shown in Figure 4.21.

Figure 4.21 Hyperlink anchor

When the viewer clicks the hyperlink, the page will automatically scroll to the anchor position of the href attribute value name.

— Note: The tag that defines the anchor does not necessarily need specific content, it is just a positioning.

4.5.5 Email, FTP and Telnet links

Hyperlinks can also further expand the functions of web pages. The more commonly used ones are email, FTP and Telnet connections. To complete the above functions, you only need to modify the href value of the hyperlink. The format for sending emails is:

Send me an email

The email address must be complete, such as intel@qq.com.

As mentioned earlier, the http protocol is used to browse the web, and the FTP server is connected using the FTP protocol. The link format is as follows:

Link text

The difference between FTP server link and web page link lies in the protocols used. FTP requires login permission from the server administrator. However, some FTP servers can be accessed anonymously and some public files can be obtained. Similarly, a similar method is used to connect to the server using the Telnet protocol, with the following format:

Link text

The telnet protocol is rarely used, and the http protocol is mostly used. Create a web page file in the D:web directory, name it mail.htm, and write the code as shown in Code 4.21.

Code 4.21 Other settings for hyperlinks: mail.htm

Send me an E-mail

Connect to FTP server

Connect to Telnet server

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Enter http://localhost/mail.htm in the browser address bar, and the browsing effect is as shown in Figure 4.22.

Figure 4.22 Other settings for hyperlinks