Simple If else program in C++ where program it ask user to enter age at runtime and then it will then that you are young or old.
#include < iostream>
using namespace std;
int main()
{
int age;
cout<<"Please input your age: ";
cin>> age;
if ( age <= 30 ) {
cout<<"You are pretty young!\n";
}
else {
cout<<"You are really old\n";
}
}