How regular expression OR operator is evaluated

Question

In T-SQL I have generated UNIQUEIDENTIFIER using NEWID() function. For example:

723952A7-96C6-421F-961F-80E66A4F29D2

Then,

Answer 1

Your Regex ^.{8}|.{12}$|.{4} evaluates to:

Starting with any character except \n { Exactly 8 times }

OR any character except \n { Exactly 12 times }

OR any character except \n { Exactly 4 times } globally

This means that anything after 4 characters in a row will be matched because somewhere in a string of >4 characters there are 4 characters in a row.

1 [false]

12 [false]

123 [false]

1234 [true]

12345 [true]

123456 [true]

1234567 [true]

12345678 [true]

123456789 [true]

1234567890 [true]

12345678901 [true]

123456789012 [true]

You might be looking for:

^.{8}$|^.{12}$|^.{4}$

Which gives you:

1 [false]

12 [false]

123 [false]

1234 [true]

12345 [false]

123456 [false]

1234567 [false]

12345678 [true]

123456789 [false]

1234567890 [false]

12345678901 [false]

123456789012 [true]