Using nested IF statements
If an IF
statement contains an IF
statement
as one of its possible branches, the IF
statements
are said to be nested. Theoretically, there is no limit
to the depth of nested IF
statements.
About this task
However, use
nested IF
statements sparingly.
The logic can be difficult to follow, although explicit scope terminators
and indentation can help. If a program has to test a variable for
more than two values, EVALUATE
is probably a better
choice.
The following pseudocode depicts a nested IF
statement:
IF condition-p
IF condition-q
statement-1
ELSE
statement-2
END-IF
statement-3
ELSE
statement-4
END-IF
In the pseudocode above, an IF
statement
and a sequential structure are nested in one branch of the outer IF
.
In this structure, the END-IF
that closes the nested IF
is
very important. Use END-IF
instead of a period, because
a period would end the outer IF
structure also.
The following figure shows the logic structure of the pseudocode above.