How to remove html tags in php

In web development, we often need to obtain user input content from some rich text editors, but these content often contain many HTML tags and styles. Although these labels and styles are beautiful, they are often not suitable for us to use in all scenarios. So, how to remove these html tags? In php, we can use the following method to remove html tags.

1. Use the strip_tags function

strip_tags is a built-in function in PHP, and its function is to remove the html tags in the string. The function prototype is as follows:

string strip_tags ( string $str [, string $allowable_tags ] )

Among them, $str represents the string that needs to be processed; $allowable_tags is an optional parameter, indicating the tag name that is not to be deleted, and multiple tags are separated by spaces.

The sample code is as follows:

$str = '<p><strong>这是一段富文本内容。 </strong></p>';
echo strip_tags($str); //输出：这是一段富文本内容。

If you need to keep some tags without deleting them, you can use the second parameter. For example, to keep the two tags p and strong without deleting them, you can write like this:

$str = '<p><strong>这是一段富文本内容。 </strong></p>';
echo strip_tags($str, '<p><strong>'); //输出：<p><strong>这是一段富文本内容。 </strong></p>

It should be noted that the strip_tags function can only remove html tags and does not work for any script tags or JavaScript codes.

2. Use regular expressions to remove html tags

Regular expressions are a convenient and efficient tool for processing text. In php, we can use regular expressions to remove html tags. The following is an example:

$str = "<p><strong>这是一段富文本内容。</strong></p>";
$str = preg_replace('/<[^>]*>/', '', $str);
echo $str; //输出：这是一段富文本内容。

Regular expression'/<[^>]*>/' means matching all html tags and using the preg_replace function to replace them with Empty string.

It should be noted that the method of using regular expressions is more flexible, but also has higher performance requirements.

Summary:

In web development, removing html tags is a common requirement. PHP provides the strip_tags function and regular expression method to achieve this function. Which method to use depends on the specific scene requirements. But in general, using the strip_tags function is simpler and more direct, and using regular expressions is more efficient and flexible.

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