Master Mainframe Technologies - COBOL, JCL, DB2, VSAM, CICS & More
ABEND Codes SQLCODEs File Status Interview Prep Contact
← Back to String Handling
String Handling | Intermediate | COBOL

Reverse a String

Problem Description

Accept a string and display it reversed.

Expected Output

Input: HELLO -> Output: OLLEH

Hints

Use reference modification to access characters.

Solution

IDENTIFICATION DIVISION. PROGRAM-ID. REVERSE. DATA DIVISION. WORKING-STORAGE SECTION. 01 WS-INPUT PIC X(50). 01 WS-OUTPUT PIC X(50). 01 WS-LEN PIC 9(2). 01 WS-I PIC 9(2). 01 WS-J PIC 9(2). PROCEDURE DIVISION. DISPLAY "ENTER A STRING: ". ACCEPT WS-INPUT. MOVE FUNCTION LENGTH(FUNCTION TRIM(WS-INPUT)) TO WS-LEN. MOVE 1 TO WS-J. PERFORM VARYING WS-I FROM WS-LEN BY -1 UNTIL WS-I < 1 MOVE WS-INPUT(WS-I:1) TO WS-OUTPUT(WS-J:1) ADD 1 TO WS-J END-PERFORM. DISPLAY "REVERSED: " WS-OUTPUT. STOP RUN.

Explanation:

Reference modification: VAR(start:length) accesses substring.