- A block
IF
starts with an IF <test> THEN
line and ends with an ENDIF
line.
if value LT 0 then
say "the value is negative"
endif
- The block
IF
can also have an ELSE
clause that is executed
when the test is false.
if value LT 0 then
say "the value is negative"
else
say "the value is not negative"
endif
- The block
IF
can have one or more ELSEIF
blocks that
test for other other conditions when the previous one(s) have not been satisfied.
if value LT 0 then
say "the value is negative"
elseif value EQ 0 then
say "the value is zero"
else
say "the value is positive"
endif
- The use of
THEN
is technically optional, but is strongly recommended.