How to filter strings in PHP

We all knowSample Code for PHP to filter strings:

1. <? Php
2. Nl2br ();
3. // N<Br/> 
4. Addslashes (); stripslashes ();
5. // Escape special characters for database operations
6. Chop ();
7. // Remove spaces on the right of the string
8. Trim ();
9. // Remove all spaces in the string
10. Ltrim ();
11. // Remove the left space of the string
12. Htmlspecialchars ();
13. // Convert '$ ','"','<','>'Is the corresponding html Object
14. Htmlentities ();
15. // Convert all html tags to corresponding html entities
16. Array explode (string separator, string str );
17. // Split the string
18. String implode (string separator, array arr );
19. // Connection string
20. Strtoupper (); strtolower ();
21. // Converts uppercase and lowercase letters.
22. Ucfirst ();
23. // Only converts the first character to uppercase.
24. Ucwords ();
25. // Convert the first letter of each word to uppercase.
26. ?>

We hope that you can gain an in-depth understanding of this knowledge point through the PHP filter string method described in this article.