What Delimiter to use for preg_replace in PHP (replace working outside of PHP but not inside)

by

preg_replace() requires a delimiter character:

preg_replace("/$pat/" ...

Traditionally it’s the forward slash, but it can be any character – especially when you need the forward slash in the regex itself you can resort to another character.

This flexibility allows you to express "/http:\/\/foo\/bar\//" (“leaning toothpick syndrome”) as "!http://foo/bar/!".

The delimiter character is necessary to separate the regex from the regex flags (a.k.a. “modifiers”), for example:

preg_replace("/$pat/i" ...

…this uses the i flag to declare a case-insensitive regex.

More Related Contents:

  1. Warning: preg_replace(): Unknown modifier
  2. Replace preg_replace() e modifier with preg_replace_callback
  3. Replace URLs in text with HTML links
  4. php regex to match outside of html tags
  5. Remove multiple whitespaces
  6. Convert plain text URLs into HTML hyperlinks in PHP
  7. Convert string into slug with single-hyphen delimiters only
  8. PHP remove special character from string
  9. Replace multiple newlines, tabs, and spaces [duplicate]
  10. Extract URL from string
  11. Regular expressions for a range of unicode points PHP
  12. How to remove diacritics from text?
  13. PHP using preg_replace : “Delimiter must not be alphanumeric or backslash” error
  14. Replace only first match using preg_replace [duplicate]
  15. Unknown modifier ‘/’ error in PHP [duplicate]
  16. Regex to strip comments and multi-line comments and empty lines
  17. Replace tabs and spaces with a single space as well as carriage returns and newlines with a single newline
  18. How to properly escape a backslash to match a literal backslash in single-quoted and double-quoted PHP regex patterns
  19. regular expression and forward slash
  20. Regex / DOMDocument – match and replace text not in a link
  21. PHP Preg-Replace more than one underscore
  22. Regex ignore URL already in HTML tags
  23. regular expression [closed]
  24. Regex to validate range of numbers from 50 to 1000 with step of 50 [closed]
  25. How do I make this preg_match case insensitive?
  26. Matching a space in regex
  27. Get numbers from string with PHP
  28. Regex & PHP – isolate src attribute from img tag
  29. What is the MM/DD/YYYY regular expression and how do I use it in php?
  30. Finding @mentions in string

Leave a Comment