Recursion In COBOL

Recursion is rarely used in Cobol. It is also boring to see this example in IBM book.

 

Identification Division.

Program-id. recutestRecursive.

**************************************** ***

* Recursive Test

**************************************** **

Environment Division.

Data Division.

Working-storage section.

01 numb PIC 9 (4) value 5.

01 fact PIC 9 (8) value 0.

 Local-storage section.

01 num PIC 9 (4 ).

Procedure division.

Move numb to num

If numb = 0 then

Move 1 to fact

Else

Subtract 1 from numb

Compute numb = numb-1

Call 'recutest'

Multiply num by fact

Compute fact = fact * num

End-if

Display num '! = 'Fact

Goback.

End program recutest.

 CodeIf there is no highlight, you will be watching it. The Code has passed the test and can be run.

There are two key points:

(1) Add the recursive keyword to the end of the program-ID segment.

(2) Use the local-storage section to save each entryProgramThe value of num.

 

For example, for each call to recutest, num in local-storage will save their respective values. In working-storage, numb only has one

Value. This is the key to implementing recursion in Cobol.