如何使用正则表达式检查2个字符？

Question

I used the following to check for two digits.

"^\d{2}$"

But how can I change this so I check for two digits or uppercase AZ?

Answer 1

2 consecutive digits or 1 uppercase character:

\d{2}|[A-Z]

2 consecutive digits or 2 consecutive uppercase characters:

\d{2}|[A-Z]{2}

2 consecutive digit / uppercase characters:

[\dA-Z]{2}

Answer 2

^[A-Z|\d]{2}$

matches AA and 11 but not A, 1, AAA, or 111 (the AZ specifies uppercase only)

Edit: This will also match 1A and C3 (see comment by Jason), if this is not what you want do not use this answer.

Answer 3

Use this, will match the items in bold only:

^\d{2}|[A-Z]{2}$

• 25
• ab
• AB
• 2A
• A3
• -23
• -AB

If you also want to match against negatives, you can try this one:

^-?\d{2}|[^-][A-Z]{2}$

And will match these

• 25
• ab
• AB
• 2A
• A3
• -23
• -AB