Educational

Category: Interview Questions

  • What are COBOL’s strengths?

    • Very strong in business data processing.
    • Handles huge amounts of data efficiently.
    • Still used in banking, finance, insurance, government systems.
    • Easy to read (English-like).

  • SEARCH and SEARCH ALL?

    • SEARCH → Linear search, works with unsorted tables.
    • SEARCH ALL → Binary search, requires sorted table, faster.

  • How does COBOL handle files?

    COBOL uses FILE SECTION in DATA DIVISION.

    • Files are processed using OPEN, READ, WRITE, CLOSE.

    Example:

    IDENTIFICATION DIVISION.
PROGRAM-ID. FILE-DEMO.

ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.

    SELECT EMP-FILE ASSIGN TO 'EMP.DAT'
ORGANIZATION IS LINE SEQUENTIAL.
    
DATA DIVISION.
FILE SECTION.
FD EMP-FILE.
01 EMP-REC.
   05 EMP-ID     PIC 9(4).
   05 EMP-NAME   PIC A(20).

WORKING-STORAGE SECTION.
01 WS-EOF PIC X VALUE 'N'.

PROCEDURE DIVISION.

    OPEN INPUT EMP-FILE
PERFORM UNTIL WS-EOF = 'Y'
    READ EMP-FILE
        AT END MOVE 'Y' TO WS-EOF
        NOT AT END DISPLAY EMP-REC
    END-READ
END-PERFORM
CLOSE EMP-FILE
STOP RUN.

  • GOBACK, and EXIT PROGRAM?

    STOP RUN → Ends the main program & returns control to OS.

    GOBACK → Returns control to caller (or OS if no caller).

    EXIT PROGRAM → Used in subprograms to return control to calling program.

  • 88 level in COBOL?

    • Level 88 → Conditional variable, used for readability in conditions.

    Example:

    01 STATUS-CODE    PIC 9(1).
   88 SUCCESS     VALUE 1.
   88 FAILURE     VALUE 0.

IF SUCCESS
   DISPLAY "Operation Successful".

  • WORKING STORAGE SECTION and LINKAGE SECTION?

    WORKING-STORAGE: Declares variables for the current program.

    LINKAGE SECTION: Declares variables that come from another program or JCL (passed parameters).

  • PERFORM and CALL?

    • PERFORM → used for executing a paragraph or section within the same program (like a loop or subroutine).
    • CALL → used for calling an external program or subprogram.

    Example:

    PERFORM CALC-PARA.      *> internal call

CALL 'SUBPROG' USING VAR1.  *> external program call

  • What is PIC clause in COBOL?

    • PIC stands for Picture Clause → defines the type & size of a variable.

    Example:

    01 NAME  PIC A(10).    *> 10 characters (Alphabetic)
01 AGE   PIC 9(3).     *> 3-digit number
01 SALARY PIC 9(5)V99. *> 5 digits + 2 decimal places

  • COMP and COMP-3?

    • COMP (Binary Storage): Data stored in pure binary format. Faster for arithmetic operations.
    • COMP-3 (Packed Decimal): Data stored in packed format (2 digits per byte). Saves space, often used in financial apps.

    Example:

    01 A  PIC 9(4) COMP.     *> Binary storage
01 B  PIC 9(4) COMP-3.  *> Packed decimal storage

  • divisions in COBOL program?

    COBOL program is divided into 4 divisions:

    1. IDENTIFICATION DIVISION – program info (name, author).
    2. ENVIRONMENT DIVISION – environment details (input-output devices).
    3. DATA DIVISION – data & variables declaration.
    4. PROCEDURE DIVISION – actual logic/code.

    Example:

    IDENTIFICATION DIVISION.
PROGRAM-ID. SAMPLE.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 NUM PIC 9(3).
PROCEDURE DIVISION.

    DISPLAY "HELLO".
STOP RUN.