programming-for-dummies

194
Making Multiple Choices with the SELECT CASE Statement
With a switch statement in a curly bracket language, like C, you can do the
following:
switch (age)
{
case 67:
case 66:
case 65: status = retired;
break;
case 21: status = working;
break;
case 15: status – student;
}
By not using the break command if the value of the age variable is 67 or 66,
the computer just continues down, line by line, until it runs the command if
the age variable was 65. Then it hits the break command directly under the
status = retired command and stops.
The switch command can be easier to read because all the matching values
(67, 66, 65, 21, and 15) appear in a vertical column. The equivalent SELECT
CASE statement can be slightly harder to read because all the values don’t
line up in a single vertical column.
Checking a range of values
The problem with the SELECT CASE statement is that it needs to match a
value exactly. Although you could type in all possible values to match, that
can get clumsy, as in the following that sets Status = retired if the Age
variable is between 65 and 75:
SELECT CASE Age
CASE 65, 67, 68, 69, 70, 71, 72, 73, 74, 75
Status = Retired
CASE 21
Status – Working
CASE 15
Status = Student
END SELECT
To avoid this problem, many languages let you check for a range of values.
So if you want to check if a variable is equal or greater than 65 and less than
or equal to 75, you could define the range of 65 TO 75 like this:
SELECT CASE Age
CASE 65 TO 75
Status = Retired
CASE 21
Status – Working