Need a regex for ONLY Alphanumeric (no pure numbers or letters) AND limit to exactly 10 characters?

Question

I've run into some issues with this one and cannot find it in past questions.

Criteria:

1. Reject pure digits
2. Reject pure letters
3. Reject any symbols
4. Accept ONLY Alphanumeric combo
5. MUST be equal to 10 characters total

Here is what I have made and the problems with each:

1. ^(?!^\d*$)[a-zA-Z\d]{10}$

   • This fails criteria #2

2. ^[a-zA-Z0-9]{10}$

   • This fails criteria #1

I have tried some others that meet all criteria but fail the 10 char limit.

Any help is appreciated.

Answer 1

You may use a second lookahead:

^(?!\d+$)(?![a-zA-Z]+$)[a-zA-Z\d]{10}$

See the regex demo and the Regulex graph:

Details

• ^ - start of string
• (?!\d+$) - a negative lookahead that makes sure the whole string is not composed of just digits
• (?![a-zA-Z]+$) - the whole string cannot be all letters
• [a-zA-Z\d]{10} - 10 letters or digits
• $ - end of string.