The switch statement simplifies complicated 'if then else' constructs in c ++ and is similar to the case statement in Delphi.  The variable to be tested comes after the switch statement, and it can be variable, an expression or the result of a function.

switch(x)
  {
     case 1 :
        {
           dosomecode1;
           break;
        }
     case 2 :
        {
           docodefor2;
           break;
        }
     case 3 :
     case 4 :
     case 5 :
     case 6 :
        {
            docodefor3456;
            break;
        }
     default :
        {
            dodefaultcode;
        }
   }

In the above example when x is 1 then code for 1 executes.  The break statement is optional, however if you do not include it   the switch statement will go through all the other comparisons, whereas with a break statement once a valid comparison is found the program executes the code segment and does not bother checking the other comparisons which is more efficient.  When x is either 3, 4, 5, or 6 the same block of code will execute in each case, and if x has none of these values then the final default code executes.  It is not mandatory to include a default switch, and it functions much like the final 'else' statement of a complicated if - then - else construct.