8-3-1

Editing Program Contents

8-3 Editing Program Contents

kDebugging a Program

A problem in a program that keeps the program from running correctly is called a “bug,” and the process of eliminating such problems is called “debugging.” Either of the following symptoms indicates that your program contains bugs that require debugging.

•Error messages appearing when the program is run

•Results that are not within your expectations

uTo eliminate bugs that cause error messages

An error message, like the one shown below, appears whenever something illegal occurs during program execution.

When such a message appears, press Jto display the place in the program where the error was caused. The cursor will be flashing at the location of the problem. Check the “Error Message Table” (page α-1-1) for steps you should take to correct the situation.

•Note that pressing J does not display the location of the error if the program is password protected. Instead, it returns to the program list screen.

uTo eliminate bugs that cause bad results

If your program produces results that are not what you normally expect, check the contents of the program and make necessary changes.

1(TOP) ..... Moves the cursor to the top of the

program

2(BTM) ..... Moves the cursor to the bottom of

the program

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