The switch statement executes one or more of a series of cases,
  based on the value of an integer expression.
  Syntax:

       switch ( expression ) body

  The switch's body typically is a block, within which any statement
  can be prefixed with one or more case labels as follows:

       case constant-expression :

  At most one statement in the body may have the label as follows:

       default :

  The switch expression is evaluated and compared to the cases.  If
  there is a case matching the expression's value, it is executed; if
  not, the default case is executed.  The switch is normally
  terminated by a break, return, or goto statement in one of the
  cases.  If there is no matching case and no default, the body of
  the switch statement is skipped.