The access modifier const can be added to the declaration of an object to make that object a constant rather than a variable. Thus, the value of the named constant cannot be altered during the program run whereas the value of the variable can be changed during the program run.
Example:
void main () {
const int a =10;
int b = 20;
a++;
cout<<"a="<<a;
b++;
cout<<"b="<<b;
}
