switch ... semantics
Switch statement is used when there are more two alternatives to select from..
selector is an ordinal expression: That means that the values it can take should be finite, countable: integer, char, bool types are acceptable but not float.
The selector type and case label type should be same.
Each case label must be distinct.
The selector expression is evaluated and compared to each of the case labels.
If the value of the selector is one of the case labels, say label x, then the statementsx is executed.