C++ Switch

A switch statement checks a variable against a list of case values. When it finds a match, it runs the code for that case. It is perfect for menus, day names, grades, and any situation with a fixed set of choices.

How switch works

You write switch followed by the variable in parentheses. Inside the braces, each case lists a possible value. The break keyword ends a case so the program jumps out of the switch. The optional default runs when no case matches.

#include <iostream>
using namespace std;

int main() {
  int day = 3;

  switch (day) {
    case 1:
      cout << "Monday\n";
      break;
    case 2:
      cout << "Tuesday\n";
      break;
    case 3:
      cout << "Wednesday\n";
      break;
    default:
      cout << "Another day\n";
  }
  return 0;
}

The default case

The default case is like the else in an if chain. It catches any value that none of the cases matched. It is optional, but including it is good practice so your program always has a sensible response.

#include <iostream>
using namespace std;

int main() {
  char choice = 'B';

  switch (choice) {
    case 'A':
      cout << "You chose Start.\n";
      break;
    case 'B':
      cout << "You chose Settings.\n";
      break;
    case 'C':
      cout << "You chose Quit.\n";
      break;
    default:
      cout << "Unknown option.\n";
  }
  return 0;
}

switch vs if...else