Is C++ variable case sensitive?

Answer 1

Yes it is.

Answer 2

thanks

Answer 3

the whole language is case sensitive.. but in defining a variable there are certain rules like u cannot use special characters except _ (underscore) and few more.. and once u defined the variable u cannot make changes to it while using it like :
int sum;
int a=2;
int b=3;
SUM=a+b;
//here sum!=SUM