COBOL Interview Questions and Answers

COBOL stands for Common Business Oriented Language and it is one of the oldest and widely used high-level programming languages. It can handle huge data processing. It is used for writing application programs. It mainly used for business, finance and administrative systems for companies.

There are five data types in Cobol:

• Alpha-numeric (X)
• Alphabetic (A)
• Numeric (9)
• Sign(S)
• Assumed decimal point(P/V)

Elementary level item. Cannot be subdivisions of other items (cannot be qualified), nor can they be subdivided themselves.

For condition name entry

For Renames clause items

Logic error. e.g., a file is opened for input and an attempt is made to write to it.

Mismatch in LRECL or BLOCKSIZE or RECFM between your COBOL pgm & the JCL (or the dataset label). You will get file status 39 on an OPEN.

PIC 9.99 is a four-position field that actually contains a decimal point

The maximum value is 99999999.

SECTION will cause all the paragraphs that are a part of the section to be performed. PARAGRAPH will cause only a particular paragraph to be performed.

Subscript refers to the occurrence of an array but index is the displacement from the beginning of the array.

An index can only be modified using PERFORM, SEARCH & SET.

In the case of Static call, the called program is a stand-alone program, it is an executable program. During run time we can call it in our called program. As about Dynamic call, the called program is not an executable program it can executed through the called program

CONTINUE is like a null statement and it continues execution, while NEXT SENTENCE transfers control to the next sentence.

File opening modes in COBOL include:

INPUT,

OUTPUT,

I-O, and EXTEND.

SEARCH – is a serial search.

SEARCH ALL – is a binary search & the table must be sorted (ASCENDING/DESCENDING KEY clause to be used & data loaded in this order) before using SEARCH ALL.

In static linking, called subroutine links into the calling program, while in dynamic linking, the subroutine & the main program will exist as separate modules. Dynamic and Static linking can be achieved by choosing either the DYNAM or NODYNAM link edit option.

Evaluate is just like a case statement or it can be used like a Nested IFs. The difference between EVALUATE and case is that ‘break’ is not used in Evaluate statement and the control comes out of the EVALUATE once a match is found.

REPLACING allows for the same copy to be used more than once in the same code by changing the replace value.

COPY <Name> REPLACING BY

ON SIZE ERROR option is raised when there is

• fixed-point overflow
• Zero raised to the zero power
• Division by 0
• Zero raised to a negative number
• A negative number raised to a fractional power.

Structured programming is logical way of programming where the functionalities are divided into modules and helps write the code logically.

Object Oriented Cobol language is a Natural way of programming in which you identify the objects, and then write functions and procedures around that object.

Local-Storage is allocated each time the program is called and will be de-allocated when the program stops via an Exit Program, Goback, Or Stop Run. It is defined in the DATA DIVISION after WORKING-STORAGE SECTION

In the INPUT PROCEDURE, the input file is opened, records are read and edited and then are released to the sorting operation. Finally the file will be closed.

[plain]RELEASE recordname FROM inputrecord[/plain]

In the OUTPUT PROCEDURE, output file is opened, the sorted record is returned to the Output record and then the record will be written. Finally the file will be closed.

[plain]RETURN file RECORD into outputrecord[/plain]

The linkage section is used to pass data from one program to another program or to pass data from a procedure to a program. It is part of a called program that maps to data items in the calling program’s working storage.

Access modes are SEQUENTIAL or DYNAMIC for the start statement.

Identification division and Program ID are mandatory for a COBOL program.

Global variables are accessible only to the batch program whereas external variables can be referenced from any batch program residing in the same system library.

Pic 9v99 is a three position Numeric field with an implied or assumed decimal point after the first position. Here, v means an implied decimal point.

Following guidelines to be following while writing Cobol program:

• Use ‘EVALUATE’ statement for constructing cases.
• Use scope terminators for nesting.
• Use in-line Perform statement for writing ‘do’ constructions.
• Use Test Before and Test After in the Perform statement while writing Do-While statements.

There are four divisions in a cobol program:

• Identification division
• Environment division
• Data division
• Procedure division

COMP-1 is a Single precision floating point and uses four bytes.

COMP2 is the double precision floating number and uses eight bytes.

The Purpose of Pointer is to specify the leftmost position within receiving field where the first transferred character will be stored.

The SEARCH can be applied to a table

• Which has OCCURS clause
• INDEXED BY phrase
• Search Index must have some initial value
• Set the index value to 1

SORT can be performed when

• Input and Output files must remain closed
• Working file must have a select clause
• Input and Output files have FD entries
• Work file should have short description in File Section

Scope terminators are mandatory for in-line PERFORMS and EVALUATE statements. Make scope terminator as explicit for good coding standards.

The REDEFINES clause allows you to use different data description entries to describe the same computer storage area. OR The REDEFINES clause allows the same memory area to be described by different data items

Before the REWRITE is performed, the record must be open and read from the file. Therefore, the file must be opened in I-O mode for rewrite functionality.

INSPECT is used to know number of times a specific character occurs or to replace some portion of data.

There are six sections in Data Division:

• File Section
• Working Storage Section
• Local Storage Section
• Screen Section
• Report Section
• Linkage Section

Comp is for binary usage, while comp-3 indicates packed decimal.

Cobol does not allow you to directly display COMP-3. The only way you can display it is by moving the value into a variable.

A call is an actual COBOL command which provokes an external program and returns. Link is same as Call but it does not belong to a COBOL verb.

Arrays can be defined as –

05 Array1 PIC X(9) which occurs 10 times

05 Array2 PIC X(9) which occurs 20 times

A literal is a data item which consists value by itself. It cannot be referred by a name. They are constant data items. There are two types of literals:

• String / Alphanumeric Literals
• Numeric Literals

A report item is a field to be printed which has Edit Symbols.

GOBACK returns control to the calling program

STOP RUN stops the current work unit and returns control to OS

EXIT PROGRAM is used to come out of a program that has been called by another program