A regular that checks that a string consists of pairs of identical letters (they may differ in case)

Question

Regular Expressions

That is, for example, the line: AaBb is correct, but the lines: AaBv and AaBbc are not.
As I understand it, you need to use backref here, but somehow it turns out stupidity, and not what you need

Answer 1

I got the following regex:

((\w)\2)*

The 'Case insensitive' flag must be set. You can test the regular expression at regexpal.com , debuggex.com or Regular Expression Tester

Answer 2

^(?:(\w)\1)+$

Answer 3

Thank you!