Case Statement

. switch expression

begin

case value: statement

case value: statement

..

case value: statement

default: statement

end

.evaluate the expression

. find which value in the list of cases is the same as the value of the expression

. - Default value matches the expression if none of the values explicitly mentioned in the cases matches the expression

. execute the statement associated with the value found

There is a selector expression, which is to be evaluated, followed by n constant values that the expression can take. This may also include a default value which always matches the expression if no other value does. The intended translation of a switch case code to:

.evaluate the expression

. find which value in the list of cases is the same as the value of the expression.

. Default value matches the expression if none of the values explicitly mentioned in the cases matches the expression . execute the statement associated with the value found

Most machines provide instruction in hardware such that case instruction can be implemented easily. So, case is treated differently and not as a combination of if-then statements.