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B.3 Conditionals
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There are two major types of conditionals:
IF/THEN/ELSE/END IF
and
SELECT/CASE/END SELECT. The IF construct is
useful to check one or more conditions and execute a different block of code
depending on the result. For instance, say that you need to print one
statement if the user is male and under 20, another if the user is male and
between 20 and 40, and still another if the user is male and over 40. The IF
construct works well in this kind of situation.
The
SELECT construct is useful when comparing one main expression with
several values and executing a different block of code for each possible
match. For instance, suppose that in the tax program we mentioned before, you
need to execute a different block of code depending on the user's tax
bracket. SELECT CASE would let you compare
a main expression of
tax_bracket with
all the possible tax brackets (10000-15000, 15000-25000, etc.).
Here are details on
conditionals.