switch

 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.