Each variable that we use in our program must be declared at the starting of void main ( ).

Syntax-
Data-type1 variable-name1, variable-name2,...... ;
Data-type2 variable-name3, variable-name4,...... ;
Data-type3 variable-name5, variable-name6,...... ;

Example-

int first, second ;
float f1, f2 ;
char c1, c2 ;