c 2b 2b switch

1switch(expression) {
2  case x:
3    // code block
4    break;
5  case y:
6    // code block
7    break;
8  default:
9    // code block
10}

1switch(a) {
2  case -1:
3    std::cout << "a == -1" << std::endl;
4  break;
5
6  case 0:
7    std::cout << "a == 0" << std::endl;
8  break;
9
10  default:
11    std::cout << "a is something else" << std::endl;
12}

1switch (n)
2{
3    case 1: // code to be executed if n = 1;
4        break;
5    case 2: // code to be executed if n = 2;
6        break;
7    default: // code to be executed if n doesn't match any cases
8}

1switch(expression) {
2   case 1:
3      //equivalent to if(expression == 1){//do someting...}
4      //do something...
5      break; 
6    //if case 1 is true the rest of the statments arn't 
7    //evaluated because of the break
8   case 45:
9      //equivalent to else if(expression == 45){//do someting...}
10      //do something...
11      break;
12    
13   // you can have any number of case statements and default has to be last
14   default :
15      // equivalent to else{//do someting...}
16      //do something...
17}
18
19switch(expression) {
20   case 1:
21      //equivalent to if(expression == 1){//do someting...}
22      //do something...
23   case 45:
24      //equivalent to if(expression == 45){//do someting...}
25      //do something...
26   default :
27      //always runs if there are no breaks in any of the cases
28      //do something...
29}
30
31//modification of answer by Homeless Hoopoe

1switch(expression) {
2   case constant-expression  :
3      statement(s);
4      break; //optional
5   case constant-expression  :
6      statement(s);
7      break; //optional
8  
9   // you can have any number of case statements.
10   default : //Optional
11      statement(s);
12}
13

1switch (<espressione>)
2{
3case <valore costante 1>:
4// istruzioni
5break;
6
7
8case <valore costante 2>:
9// istruzioni
10break;
11...
12case <valore costante N>:
13// istruzioni
14break;
15default:
16// istruzioni
17break;
18}