COBOL: 3 Alternatives Where You Can Avoid GO TO Statements

GO TO statements kill your application performance. It is not a part of the structural design. Avoid these mistakes in your program.

GO TO Statement

GO TO statement will not give control back. It just drops control at destiny. When you compare GOTO with Perform, then Perform is a much better option.

GO TO is first introduced in FORTRAN language in 1957.

The primary criticism is that code that uses goto statements is harder to understand than alternative constructions.

You can tell in interview, if we avoid GO TO statements, you can improve performance.

Alternative: 1

Sample COBOL Program.

2020-TEST-SECTION  SECTION.
Move A To B. 
IF B > 50
GO TO 2020-EXIT 
END-IF. 
EXIT-2020. 
EXIT.

How to re-write the Code.

2020-TEST-SECTION  SECTION.
Move A To B. 
IF B > 50
CONTINUE 
END-IF. 
EXIT-2020. 
EXIT.

In the above example CONTINUE helps you to come out of your section.

Alternative: 2

2021-TEST-SECTION SECTION.
Move A To B. IF B > 50
GO TO 2021-EXIT
END-IF. 
Move B To C. 
IF C > 50
GO TO 2021-EXIT 
END-IF. 
EXIT-2021. 
EXIT.

How to Avoid GO TO Statement.

2021-TEST-SECTION SECTION.
Move A To B. IF B > 50
SET B IS TRUE
END-IF.
Move B To C.
IF C > 50
SET C IS TRUE
END-IF.
EXIT-2021.
EXIT.
*** Your Next Logic would be
IF B
PERFORM 2022-B-SECTION.
END-IF.
IF C
PERFORM
2023-C-SECTION.
END-IF.

Section and Paragraph both are different. The word SECTION you need to write in the first line of the section. No need to write anything for paragraphs. A section can contain paragraphs.

Alternative: 3

2023-TEST-SECTION SECTION.
Move A To B.
IF B > 50
GO TO 2024-TEST-SECTION
END-IF.
EXIT-2023.
EXIT.

The above way of using GO TO is a crude method. Instead, you can use code as below. The EXIT is the last statement in a section or Paragraph.

PERFORM 2023-TEST-SECTION
PERFORM 2024-TEST-SECTION
*** Sections start here.
2023-TEST-SECTION SECTION.
Move A To B. IF B > 50
CONTINUE 
END-IF. 
EXIT-2023.
EXIT.