Regex Examples dot .
Any line that has any of the xax, xbx, ..., that is any character between two x-es.
Regex: /x.x/ Input: "abcde" Input: "abxcxbde" Input: "xabcde" Input: "xabxcxde" Input: "adax xabcde" Input: "adax.xabcde" Input: "x.x" Input: "xx"
Only lines that have x.x (A real . between two x-es.)
Regex: /x\.x/
The special characters are: . * + ? ^ $ \ ( ) [ ] | { } and the delimiter: / Some of the characters change their special meaning based on position.