Explain switch statement with Example

The C switch allows multiple choice of a selection of items at one level of a conditional where it is a far neater way of writing multiple if statements:
          switch(expression)
        {
            case item1:
                 statement1;
                break;
            case item2:
                 statement2;
                break;
                                                             case itemn:
            case itemn:
                statementn;
                break;
            default:
                 statement;
                 break;
        }
In each case the value of itemi must be a constant, variables are not allowed.
The break is needed if you want to terminate the switch after execution of one choice. Otherwise the next case would get evaluated. Note: This is unlike most other languages.
We can also have null statements by just including a; or let the switch statement fall through by omitting any statements(see e.g. below).
The default case is optional and catches any other cases.
For example:-
                      switch(letter)
                {
                     case `A':
                     case `E':
                     case `I':
                     case `O':
                     case `U':
                         numberofvowels++;
                         break;
                      case ‘ ‘:
                         numberofspaces++;
                         break;
                      default:
                         numberofconsonants++;
                         break;
                }
In the above example if the value of letter is ‘A', ‘E', ‘I', ‘O' or ‘U' then numberofvowels is incremented.
If the value of letter is ‘ ' then numberofspaces is incremented.
If none of these is true then the default condition is executed, that is numberofconsonants is incremented.