Regular expression to match exact number of characters?
Solution 1:
What you have is correct, but this is more consice:
^[A-Z]{3}$
Solution 2:
Your solution is correct, but there is some redundancy in your regex.
The similar result can also be obtained from the following regex:
^([A-Z]{3})$
The {3} indicates that the [A-Z] must appear exactly 3 times.