Regex needed for IC number validation

Question

I need to validate a 12 digit number. In which,

1st & 2nd digits = less than 100

3rd & 4th digits = between 1 and 12

5th & 6th digits = between 1 and 31

And the remaining 6 digits can be any numbers from 0 to 9

Example 190131958103

Can anyone give me the regular expression which satisfies the above validation?

Answer 1

A 2-digit value is less than 100 by definition (max value is 99), so you don't need to check for that. This regex will meet your other needs:

^\d{2}(0[1-9]|1[012])(0[1-9]|[12][0-9]|3[01])\d{6}$

It starts with any 2 digits; then either 01-09 or 10-12; followed by one of 01-09, 10-19, 20-29 or 30-31; followed by 6 digits.

Demo on regex101

Update

If you can't use \d in your pattern, replace it with [0-9] i.e.

^[0-9]{2}(0[1-9]|1[012])(0[1-9]|[12][0-9]|3[01])[0-9]{6}$