Specifications

(3) Debug while executing the program
Conversation type debug is performed by obtaining information from the computer
in the
form of error message. However, there may be occasions when an error message
is not displayed yet the calculation or program result is incorrect. In cases like that
program execution can be carried progressively in steps to confirm the calculation
results along the way. and thereby isolate
the error.
There are
two ways to do this: (1) the execution process is stopped using a STOP
command; (2) execution
is performed in one Iine units using the TR (trace) mode.
• Debug using a STOP command
Example: Write the
following program.
10 Y=0
20 INPUT N,X
30 FOR 1=1 TO N
40 Y=Y+Xt2
50 NEXT I
60 PRINT Y
70 END
The value of Y. before each consecutive loop. can be viewed using a STOP statement.
Operation:
• The STOP statement should
be placed right after the calculation formula. Write a
STOP statement between line
40 and line 50.
~[1]
45 STOP GI
• The execution process will stop after the calculation on line 40 is completed and
a check
can be made then.
~~RUN.
4.
871D
?
?
------_. __ ._----------~-
STQP
• What is the value of V at this point?
YIII
L Cursor blinks
17569
-42-
STOP display