regex to check the string contains only letter and numbers but not only numbers

Question

I need a help with regex which checks the string contains only letter and numbers but not only numbers

Valid

* letters
* 1wret
* 0123chars
* chars0123
*          


        

Answer 1

This should do it:

^[0-9]*[a-zA-Z]+[a-zA-Z0-9]*$

This requires at least one character of [a-zA-Z].