programming-for-dummies

598
Branching Statements
To make the computer choose between two mutually exclusive sets of commands,
you can use an IF-THEN-ELSE statement, such as
IF condition THEN
Command
ELSE
Command
END IF
If a Boolean condition is True, the IF-THEN-ELSE statement runs the
first group of commands, but if the Boolean condition is False, the
IF-THEN-ELSE statement runs the second group of commands. An IF-
THEN-ELSE statement will always run one set of commands or the other.
A variation of this is the IF-THEN-ELSEIF statement, which uses two or
more Boolean conditions to choose which of two or more groups of commands
to run, such as
IF condition1 THEN
Command
ELSEIF condition2 THEN
Command
END IF
Whereas the IF-THEN-ELSE statement can only give the computer a choice
of two groups of commands to run, the IF-THEN-ELSEIF statement can
offer the computer two or more groups of commands to run, such as
IF condition1 THEN
Command
ELSEIF condition2 THEN
Command
ELSEIF condition3 THEN
Command
END IF
As an alternative to the IF-THEN-ELSEIF statement, you can also use the
SELECT-CASE statement, such as
SELECT CASE variable
CASE value1
Command
CASE value2
Command
CASE value3
Command
END SELECT