Tracing program logic

You can add DISPLAY statements to help you trace through the logic of the program in a non-CICS environment. If, for example, you determine that the problem appears in an EVALUATE statement or in a set of nested IF statements, DISPLAY statements in each path tell you how the logic flows. You can also use DISPLAY statements to show you the value of interim results. Scope terminators can also help you trace the logic of your program because they clearly indicate the end of a statement.

For example, to check logic flow, you might insert the following statement to determine if you started and finished a particular procedure:

DISPLAY "ENTER CHECK PROCEDURE".
       .
       .  (checking procedure routine)
       .
DISPLAY "FINISHED CHECK PROCEDURE".

After you are sure that the program works correctly, comment out the DISPLAY statement lines by putting asterisks in position 7 of the appropriate lines.