Regular expression to restrict number of digits in a string

Question

I need to have a regular expression to restrict the number of digits in a string which may contain alphabets or any other characters along with digits. Is this possible with regular expressions ?

Answer 1

The idea is to anchor beginning and end of string and allow exactly n repetitions of a digit with something else. For example, exactly 6 digits in a string:

^\D*(\d\D*){6}$