Home/ Questions/Q 8106305
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-06T00:25:42+00:00

What does this pattern ‘/\\\(?!&#|\?#)/’ match in PHP preg_replace function? Is this pattern valid?

  • 0
  1. What does this pattern '/\\\(?!&#|\?#)/' match in PHP preg_replace function?
  2. Is this pattern valid?
  3. Why there are 3 backslashes in a row \\\?
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team
    1. The pattern checks for a literal backslash not followed by &# or ?#.
    2. Yes.
    3. Because it’s written as a PHP string literal. '\\' (an escaped escape character) in a string literal resolves to the actual string '\', so the actual regular expression is /\\(?!&#|\?#)/. The backslash is escaped inside the regex so it does not escape the (. So the actual pattern looked for is \&# or \?#.
    • 0