javascript regex match single or range

Question

How can I match with regex (javascript) below two cases:

• pattern case 1: any letter colon any 1 or 2 digits (ie A:1)
• pattern case 2: any letter colon any 1 or 2 digits dash any letter:any 1 or 2 digits (ie A:1-A:12)

I tried: ^([AZ]{1}:(\\d+)) which matches only first case

Thanks

Answer 1

This should work. It restricts the possible number of digits after the letter (1 or 2) and it also covers the second case:

^[A-Z]:\d{1,2}(-[A-Z]:(\d{1,2}))?$

Answer 2

You may use this regex t make 2nd part an optional match:

/^[a-zA-Z]:\d{1,2}(?:-[a-zA-Z]:\d{1,2})?$/gm

RegEx Demo

Answer 3

Uses Positive lookahead = (?=...)

^([A-Z]{1}\:\d{1,2}(\-(?=[A-Z]{1}:\d{1,2}))?)+$

Regex Online