Case Statement

Describes the case multipath conditional statement

This statement is an alternative to the if-then-else conditional statement. The case construct is more efficient and easier to read when you need to execute one block of code among many, based on the value of a single parameter.

Syntax:

case <expression>
when <case1> then
    <statements>
[when <cases2> then
    <statements>]
	...
	
[when <caseN> then
    <statements>]
[else
    <statements>]
end

There can be zero or more when-then statement blocks, though normally there will be more than one.

A given when expression can check for more than one value, where each value is placed in a comma-delimited list:

case x
when 1 then
    display "x is equal to one"
when 2,3,4,5,6 then
    display "x is a value between two and six"
else
    display "x is greater than six or less than one"
end

The else block is optional. It can be used to implement a default action if no when conditions are met.

The following case example sets the string shortWeekday based on the value of dayNumber. There are seven weekdays, so if dayNumber is not 1, 2, 3, 4, 5, 6, or 7, then its value is considered to be invalid.

Example:

case dayNumber
when 1 then
    shortWeekday = "Sun"
when 2 then
    shortWeekday = "Mon"
when 3 then
    shortWeekday = "Tue"
when 4 then
    shortWeekday = "Wed"
when 5 then
    shortWeekday = "Thu"
when 6 then
    shortWeekday = "Fri"
when 7 then
    shortWeekday = "Sat"
else
    shortWeekday = "This is not a valid weekday!"
end