Find substrings in string where substring encapsulated in specific character

Question

I have a string in the format:

\"The quick __grey__ fox jumps over the lazy __brown__ dog.\"

And I want to find and replace any words (or somet

Answer 1

To find some substring between two closest identical delimiters, use lazy dot matching:

$pattern = '/__(.*?)__/';

See demo

To also match newlines, use /s modifier:

$pattern = '/__(.*?)__/s';