Exact n times repetition quantifier {n}
Q
What is the exact n times repetition quantifier? How to use it?
How to write a regular expression using a repetition quantifier to capture Visa card numbers that have 16 digits like this: 4111111111111111?
✍: FYIcenter.com
A
The "exact n times" repetition quantifier allows us to repeat a pattern unit exactly n times in the matching process. The "exact n times" repetition quantifier is '{n}' and it needs be placed immediately after the pattern unit. For example:
\d{2}-\d{2}-\d{4} # matches date strings in mm-dd-yyyy format
The regular expression to capture 16-digit Visa card numbers is:
4\d{15}
4 - matches '4', the starting digit of all Visa numbers
\d{15} - repeating \d exactly 15 times
2013-01-26, 0👍, 0💬