Entering numbers in a string no more than n times

Question

Regular Expressions

How to write a regular expression that checks for occurrence in a word of latin characters no more than 3 digits? Non-consecutive occurrence of numbers.

My wild solution:
(^[a-z]*[0-9]{0,1}[a-z]*[0-9]{0,1}[a-z]*[0-9]{0,1}[a-z]*$)|(^[a-z]*[0-9]{0,2}[a-z]*[0-9]{0,1}[a-z]*$)|(^[a-z]*[0-9]{0,1}[a-z]*[0-9]{0,2}[a-z]*$)|(^[a-z]*[0-9]{0,3}[a-z]*$)

Answer 1

^(?:[a-z]*[0-9]?[a-z]*){0,3}$
but you need to check all the cases.

Answer 2

There are two small problems in m_z's answer : "not numbers" - only a-z, better ^\d, and poor speed on failed checks, because the group on the left and right can be formed in n ways. Here is a slightly improved version:
^(?:[^\d]*\d){0,3}[^\d]*$
In general, if speed is critical, you can use 10 REPLACE to remove the numbers and compare the length with the length of the original string. Maybe it will be faster (or maybe not).

Answer 3

can pull out the regular expression all the numbers and calculate the length of the resulting string?