(?:\d[ -]*?){13,16} - confused with the priority that is given in matching the pattern to the given regex

Question

I'm confused why this pattern captures 4564-1234-4325-2146, even though it has 19 digits including '-' The above pattern only captures 4564-1234435-2146-8 leaves the last hyphen and the digit 8

Answer 1

It captures 13-16 digits, each followed by zero or more spaces or dashes (the [ -]*?). In other words, the {13,16} applies to the entire group (?:\d[ -]*?). So, it could capture, for example, 1--2-3--4-5-6 7-----8-9-0-1-2-3-4-5-6-. In your sample case, it captures these 16 chunks:

• 4
• 5
• 6
• 4-
• 1
• 2
• 3
• 4-
• 4
• 3
• 2
• 5-
• 2
• 1
• 4
• 6