Why does the regex work not as expected?

Question

There is a string which can have one or several string ranges. These are correct strings:

\"\"
\"asd-asd\"
\"asd-asd;asd-asd\"
\"asd-asd;asd-asd;\"
\"asd-asd;asd         


        

Answer 1

You need to make your regex a little more complicated:

^([^;-]+-[^;-]+(;[^;-]+-[^;-]+)*)?$

Explanation:

^               # Start of the string
(               # Start of first group:
 [^;-]+-[^;-]+  # Match one "asd-asd"
 (              # Start of second group
  ;             # Match ;
  [^;-]+-[^;-]+ # Match another "asd-asd"
 )*             # Repeat the second group any number of times (including zero)
)?              # Make the entire first group optional     
$               # End of string