Using match1 ---> ^(?<a>a=(\d)).*?(?<b>b=(\d)).*?(?<c>c=(\d))$

Input1: a is a=1 and b is b=2 and c is c=3
Input2: didn't match


Using match2 ---> ^(?<a>a=(\d)).*?(?<b>b=(\d))?.*?(?<c>c=(\d))$

Input1: a is a=1 and b is  and c is c=3
Input2: a is a=1 and b is  and c is c=3