PHP function strip_A Brief Analysis of bug in tags

PHP function strip_tags provides the ability to remove HTML and PHP tags from a string, which attempts to return the result of removing empty, HTML, and PHP tags from a given string, str.

Since strip_tags() cannot actually validate HTML, incomplete or broken labels will result in more data being deleted.

For example, the following code:

<div>string</div>string<string<b>hello</b><div>string</div>

Via strip_tags ($str, ' < div > ') Filtering, we may expect the following results:

<div>string</div>string<stringhello<div>string</div>

The result is:

<div>string</div>string

This is all due to the red left angle bracket, checking PHP's documentation, and having a warning:

Since strip_tags() cannot actually validate HTML, and incomplete or broken labels will result in more data being deleted.

Since you cannot verify code correctness before performing filtering, you encounter a label-related character, " < "Or" > "The code behind it hangs up!