How to remove html tags in php (three methods)

With the continuous development of Internet technology, website development has become increasingly complex and enriched. In website maintenance and development, HTML code is often used. Although HTML is the basis of web pages, sometimes we need to extract plain text from HTML, so we need to remove HTML tags. In response to this need, this article will introduce how to use PHP to remove HTML.

1. Use the strip_tags function to remove HTML

In PHP, the strip_tags function is specially used to remove HTML tags. The usage of this function is as follows:

strip_tags($str, $allowTags)

Among them, $str is the string to be processed, $allowTags is an optional parameter, which refers to the HTML tags that are allowed to be retained. If not specified, all HTML will be Tags are removed. The following is a sample code:

$html = '<p>这是一段带有HTML标签的文本，<a>这是链接</a>。</p>';
echo strip_tags($html);

The output result is:

这是一段带有HTML标签的文本，这是链接。

This code will remove HTML tags and keep only the text.

2. Use regular expressions to remove HTML

In addition to using the strip_tags function, you can also use regular expressions to remove HTML tags. It should be noted that before using regular expressions, you need to understand the basic syntax of HTML tags.

HTML tags are wrapped by angle brackets and have a start tag and an end tag. The opening tag starts with ""; the closing tag starts with "" and ends with ">". Tag names consist of letters, numbers, and underscores.

The following is a simple regular expression example code that can be used to remove HTML tags:

$html = '<p>这是一段带有HTML标签的文本，<a>这是链接</a>。</p>';
echo preg_replace('/]+>/u', '', $html);

The output result is:

这是一段带有HTML标签的文本，这是链接。

This code will match all "< characters between ;" and ">" and replace them with the empty string.

3. Use the DOMDocument class to remove HTML

In addition to the above two methods, you can also use PHP's DOMDocument class to remove HTML tags. The advantage of this method is that it can avoid parsing errors caused by irregular HTML codes. The sample code is as follows:

$html = '<p>这是一段带有HTML标签的文本，<a>这是链接</a>。</p>';

$dom = new DOMDocument(); // 创建一个DOMDocument对象
$dom->loadHTML($html); // 将HTML字符串加载到对象中

echo $dom->textContent; // 输出内容

The output result is:

这是一段带有HTML标签的文本，这是链接。

The DOMDocument class parses the HTML code into a DOM tree, and then you can use the methods provided by this class to operate the elements of the DOM tree, such as getting The element's tag name and attributes, etc.

Summary

HTML tags can be easily removed through the above three methods, but you need to choose which method is more suitable for the current scenario based on actual needs. If the HTML code is relatively standardized, it is recommended to use the strip_tags function or the regular expression method because they are faster; if more flexibility is required, it is recommended to use the DOMDocument class to parse the HTML code.

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