1 or 0 times repetition quantifier ?
Q
What is the 1 or 0 times repetition quantifier? How to use it?
How to write a regular expression using a 1 or 0 times repetition quantifier to capture both spellings of skilful and skillful?
✍: FYIcenter.com
A
The "1 or 0 times" repetition quantifier allows us to create a special logical OR operation of "match the pattern unit or nothing". The "1 or 0 times" repetition quantifier character is '?' and it needs be placed immediately after the pattern unit. For example:
colou?r # repeat 'u' 1 or 0 times, same as colo(u|)r arm(strong)? # repeat 'strong' 1 or 0 times, same as arm(strong|)
The regular expression to capture both skilful and skillful is:
skill?ful
l? - repeat 'u' 1 or 0 times
2013-01-26, 0👍, 0💬