if … else
An example
#include <iostream.h>
int main() {
   // define two integers
   int x = 3;
   int y = 4;
   //print out a message telling which is bigger
   if (x > y) {
     cout << "x is bigger than y" << endl;
   } else {
     cout << "x is smaller than y" << endl;
   }
   return 0;
}