HP 40gs, Руководство пользователя, Страница: 366 / 444

21-18 Programming
Example
1
X
A
:
IF A==1
THEN MSGBOX " A EQUALS 1"
:
END:
IF... THEN... ELSE...
END
Executes the true-clause sequence of commands if the test-
clause is true, or the false-clause sequence of commands
if the test-clause is false.
IF test-clause
THEN true-clause ELSE false-clause END
Example
1
X
A
:
IF A==1 THEN
MSGBOX "A EQUALS 1"
:
ELSE
MSGBOX "A IS NOT EQUAL TO 1"
:
A+
1
X
A
:
END:
CASE...END
Executes a series of test-clause commands that execute
the appropriate
true-clause sequence of commands. Its
syntax is:
CASE
IF
test-clause
1
THEN true-clause
1
END
IF test-clause
2
THEN true-clause
2
END
.
.
.
IF test-clause
n
THEN true-clause
n
END
END:
When CASE is executed, test-clause
1
is evaluated. If the
test is true, true-clause
1
is executed, and execution skips
to END. If test-clause
1
if false, execution proceeds to test-
clause
2
. Execution with the CASE structure continues until
a true-clause is executed (or until all the test-clauses
evaluate to false).
IFERR...
THEN...
ELSE…
END...
Many conditions are automatically recognized by the HP
40gs as
error conditions and are automatically treated as
errors in programs.
hp40g+.book Page 18 Friday, December 9, 2005 1:03 AM