Does html belong to web or php?-Front-end Q&A-php.cn

Does html belong to web or php?

青灯夜游

Release： 2023-01-31 18:27:54

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html belongs to the web and is the development of web front-end pages; while php belongs to back-end program development. HTML stands for Hypertext Markup Language used to develop web pages and especially web design. It is the simplest language for writing web pages; HTML can only write static pages, and website content cannot be managed using HTML. In order to implement dynamic pages, in addition to using HTML and CSS Other things are needed, such as php.

Does html belong to web or php?

The operating environment of this tutorial: Windows 7 system, HTML5 version, Dell G3 computer.

html belongs to the development of web front-end pages; while php belongs to back-end program development.

html introduction

HTML stands for Hypertext Markup Language used to develop web pages and especially web design and is used to write web pages The simplest language. It is mainly written using HTML element tags, and is mainly composed of HTML elements, opening tags and closing tags>; the data between these tags is usually the content.

The main goal of HTML is to allow web browsers to parse and display content written between tags, and the purpose of these HTML tags is to describe the content of the page.

HTML can only write static pages, and website content cannot be managed using HTML. In order to implement dynamic pages, in addition to using HTML and CSS, you also need other things, such as: php.

Does html belong to web or php?

In the picture above: The PHP script processes the data saved on the server, and the processed data is reflected to the user and site administrator as an HTML template.

Three PHP/HTML hybrid methods

PHP as a back-end language, in order to output to the browser and let the browser present it , it is inevitable to output HTML code. Here are three PHP/HTML mixing methods I have used

1. Single/double quotation mark enclosing method

This is the most basic method. The usage is as follows

<?php
 echo &#39;
 <!DOCTYPE html>
 <html>
   <head>
     <title> </title>
   </head>
   <body>
     <span>测试页面</span>
   </body>
 </html>
 &#39;;
?>

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This is the simplest method. Just wrap it in single quotes

As for the difference between double quotes and single quotes, it is thatThe former parses the variables within the quotes, while the latter does not parse the variables within the quotes. See the example below

<?php
 $Content=&#39;Hello!&#39;;
 echo "$Content";
 echo &#39;<br>&#39;;
 echo &#39;$Content&#39;;
 ?>

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Output

1 Hello!
2 $Content

It can be seen that the variable name in the string surrounded by double quotes is automatically parsed into the variable value. If surrounded by single quotes, the variable name will still be displayed

There are two disadvantages to writing this way

1. If the output content contains the single / Double quotes will be extremely difficult to deal with, because PHP cannot determine whether the quotes belong to the program or the output content, so an error will be reported

2. Write some modern text like this Editor (such as SublimeText) There will be no way to syntax colorize the content of output surrounded by quotes, and it will be extremely difficult to detect if some formatting problems occur. The picture is a screenshot of SublimeText3. The top one is the normal coloring, and the bottom one is the coloring surrounded by quotes

2. Use HEREDOC/ NOWDOC

##HEREDOC and NOWDOC are a new feature that PHP5.3 began to support. It allows the use of a custom identifier to surround text in the program, while HEREDOC and NOWDOC The relationship is similar to that between double quotes and single quotes.

The former parses the variables in the block, while the latter does not parse the variables in the block

Introduced below The usage of HEREDOC and NOWDOC

<?php
 $Content=&#39;Hello!&#39;;
 
 //下面写出了一个HEREDOC，其中标识LABEL可以自定义为任何字符串，但要保证开头的标识和结尾的标识一样
 echo <<<LABEL
 $Content
 LABEL;
 //结尾的方法：另起一行，打上LABEL。注意结尾的标识前面和后面不要插入任何字符，空格也不行
 
 echo &#39;<br>&#39;;//为了演示方便换行
 
 //NOWDOC和HEREDOC的书写方式差别在于NOWDOC的标识符需要用单引号包围
 echo <<<&#39;LABEL&#39;
 $Content
 LABEL;
 //其他无异
 
 ?>

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You can also refer to the wiki about these two on PHP.net:

https://wiki.php.net/rfc /heredoc-with-double-quotes

Writing with HEREDOC/NOWDOC perfectly solves the problem of surrounding quotation marks, but it still does not solve the problem of invalid syntax coloring

3. Embed PHP program blocks in HTML (recommended)

This is a very suitable method, and this method is widely used in WordPress templates such as

## and other occasions. It is also more convenient to write. Just write the relevant code directly where you need to output it, like the following

<?php
 
 //首先在这里写好相关的调用代码
 function OutputTitle(){
   echo &#39;TestPage&#39;;
 }
 function OutputContent(){
   echo &#39;Hello!&#39;;
 }
 
 //然后再下面调用相关函数就可以了
 ?>
 
 <!DOCTYPE html>
 <html>
   <head>
     <title><?php OutputTitle(); ?></title>
   </head>
   <body>
     <span><?php OutputContent(); ?></span>
   </body>
 </html>

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I think this method is the best among the three methods, but doing this The disadvantage is that if there are too many such code blocks, it will seriously affect program reading.

Recommended learning: "

PHP Video Tutorial

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