C++ Tutorial/Operators statements/tenary operator

Материал из C\C++ эксперт
Перейти к: навигация, поиск

A Demonstration of the Conditional Operator

#include <iostream>
using namespace std;
int main()
{
   int x, y, z;
   cout << "Enter two numbers.\n";
   cout << "First: ";
   cin >> x;
   cout << "\nSecond: ";
   cin >> y;
   cout << "\n";
   if (x > y)
      z = x;
   else
      z = y;
   cout << "After if test, z: " << z;
   cout << "\n";
   z =  (x > y) ? x : y;
   cout << "After conditional test, z: " << z;
   cout << "\n";
   return 0;
}

Need parentheses around the conditional expression.

#include <iostream>
using namespace std;
int main(){
   int x, y;
   cout << "Enter two integers: ";
   cin >> x >> y;
   cout << x << ( x == y ? " is" : " is not" ) 
        << " equal to " << y << endl;
   return 0;
}

Use the ? operator to prevent a division by zero

#include <iostream>
using namespace std;
int div_zero();
int main()
{
  int i = 1, j = 0, result;

  // This statement prevents a divide by zero error.
  result = j  ?  i : j;
  cout << "Result: " << result;
  return 0;
}
Result: 0

Using the conditional operator to select output

#include <iostream>
using std::cin;
using std::cout;
using std::endl;
int main() {
  int mice = 1;
  cout << "You have "
       << mice
       << (mice == 1 ? " mouse " : " mice ")
       << "in total."
       << endl;
  return 0;
}
You have 1 mouse in total.