REGEX - Matching any character which repeats n times

Question

How to match any character which repeats n times?

Example:

for input: abcdbcdcdd
for n=1:   ..........
for n=2:    .........
for n=3:            


        

Answer 1

With .NET regular expressions you can do following:

(\w)(?<=(?=(?:.*\1){n})^.*) where n is variable

Where:

• (\w) — any character, captured in first group.
• (?<=^.*) — lookbehind assertion, which return us to the start of the string.
• (?=(?:.*\1){n}) — lookahead assertion, to see if string have n instances of that character.

Demo