Why are html and php mixed? Four ways to mix html and php-PHP Tutorial-php.cn

Why are html and php mixed? Four ways to mix html and php

怪我咯

Release： 2023-03-10 19:08:01

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The following editor will bring you a summary of four methods of PHP/HTML mixed writing. The editor thinks it’s pretty good, so I’ll share it with you now and give it as a reference. Let’s follow the editor and take a look.

PHP is a back-end language. In order to output it to the browser for the browser to display, it is inevitable to output HTML code. The following is an introduction to the three methods I have used. A PHP/HTML hybrid method

1. Single/double quotation mark enclosing method

This is the most basic method. The usage is like 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 with single quotes

As for the difference between double quotes and single quotes, it lies inThe former parses the quotes The latter does not parse variables within quotes, see the following example

<?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, while the variable name

## is still displayed when surrounded by single quotes. #There are two disadvantages to writing this way

1. If the output content contains single/double quotes, it will be extremely difficult to process, because PHP cannot determine whether the quotes belong to the program or not. Output content, so an error will be reported

2. Write some modern text in this way

Editor (such as SublimeText) will not be able to syntax color the output content surrounded by quotation marks, if some formatting problems occur It will be extremely difficult to find. The picture is a screenshot of SublimeText3. The top one is the normal coloring, and the bottom one is the coloring surrounded by quotation marks

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-quotesWriting 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.

4. Use the front-end

template engine As the importance of the front-end is increasing day by day in the entire web development, now Front-end/back-end engineers are gradually being separated into two professions. Therefore, in order to ensure that front-end/back-end engineers can cooperate with each other and make the things developed by front-end development and back-end development more perfect, a series of front-ends have gradually been spawned Template

engines, such as Smarty. The implementation code written using Smarty is very readable, which makes the separation of front/back end more efficient and convenient. Interested students can search and find out

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