COBOL Interview questions

PART-1

These COBOL interview questions cover various aspects of the COBOL programming language, including data handling, file processing, and error handling. Reviewing these questions and answers will help you prepare for your COBOL interview and demonstrate your knowledge of this language commonly used in the business domain.

1. What is COBOL, and why is it used in the business domain?

Answer: COBOL is a high-level programming language primarily used in the business domain for developing applications related to finance, banking, insurance, and data processing. It is well known for its better readability and maintainability.

2. Explain the significance of the “DATA DIVISION” in a COBOL program.

Answer: The “DATA DIVISION” in COBOL is used to define data structures, record layouts, and data files. It plays a crucial role in specifying the data that the program will process and manipulate.

3. What is the maximum length of a COBOL level number, and what does it represent?

Answer: The maximum length of a COBOL level number is 49. It represents a group item that contains subordinate data items or group items. It is typically used for organizing data hierarchies.

4. Explain the difference between “77-level” and “01-level” data items in COBOL.

Answer:

• “77-level” represents individual data items or elementary fields.
• “01-level” represents a group item, which can contain other data items, including other group items.

5. What is a “PIC” clause in COBOL, and what is its purpose?

Answer: The “PIC” (Picture) clause in COBOL is used to specify the data type, format, and size of a data item. It defines how data is stored in memory and displayed in output.

6. What is the purpose of the “REDEFINES” clause in COBOL?

Answer: The “REDEFINES” clause is used to specify that two or more data items share the same memory location. It allows multiple data items to be mapped to the same storage, effectively redefining their representation.

7. What is the difference between “SET” and “MOVE” statements in COBOL?

Answer:

• “SET” is used to initialize a data item to a specific value without type conversion.
• “MOVE” is used to copy data from one data item to another, including type conversion if necessary.

8. How can you perform arithmetic operations in COBOL?

Answer: COBOL provides arithmetic verbs such as “ADD,” “SUBTRACT,” “MULTIPLY,” and “DIVIDE” for performing arithmetic operations on numeric data items. These verbs can be used with appropriate operands.

9. What is the purpose of the “PERFORM” statement in COBOL?

Answer: The “PERFORM” statement is used for implementing loops or repetitive operations in COBOL programs. It allows a specific section of code to be executed multiple times based on a condition.

10. Explain the difference between “CALL” and “PERFORM” in COBOL.

Answer:

• “CALL” is used to transfer control to another program or subroutine, which may or may not be written in COBOL.
• “PERFORM” is used to execute a specific section of code within the same program, often used for looping and repetitive tasks.

11. What is the “88-level” condition in COBOL, and how is it used?

Answer: The “88-level” condition in COBOL is used to define condition names for data items. It allows you to create more readable and self-explanatory conditions in your code. For example, you can define CONDITION-TRUE and CONDITION-FALSE for a Boolean flag.

12. Explain the concept of “OCCURS” clause in COBOL.

Answer: The “OCCURS” clause is used to define the number of times a data item can occur in an array or table. It specifies the size and dimensionality of the array or table.

13. What is the importance of “IS INITIAL” in COBOL?

Answer: “IS INITIAL” is used in COBOL to specify that a data item should be initialized to its default initial value, which is typically zero for numeric data and spaces for alphanumeric data.

14. What is the purpose of the “STRING” statement in COBOL?

Answer: The “STRING” statement in COBOL is used for concatenating and formatting strings. It allows you to combine multiple strings into one and format the resulting string as needed.

15. How can you handle file processing in COBOL?

Answer: COBOL provides file control verbs such as “OPEN,” “READ,” “WRITE,” and “CLOSE” for handling file operations. You can use these verbs to read from and write to files.

16. What is the difference between “SEQUENTIAL” and “INDEXED” file access in COBOL?

Answer:

• “SEQUENTIAL” file access reads records in the order they appear in the file.
• “INDEXED” file access uses an index or key to locate and retrieve specific records from the file.

17. What is the “FD” (File Description) section in COBOL used for?

Answer: The “FD” section in COBOL is used to describe the structure and attributes of a file, including the record format, file organization, and access mode.

18. How can you handle exceptions and errors in COBOL programs?

Answer: COBOL provides the “ON EXCEPTION” and “USE” clauses to handle exceptions and errors. You can specify error-handling procedures to be executed when exceptions occur.

19. What is the “WORKING-STORAGE” section in COBOL, and what types of data items are typically defined in it?

Answer: The “WORKING-STORAGE” section in COBOL is used to define data items that are local to a program or subprogram and are not retained between executions. Typically, temporary variables and buffers are defined in this section.

20. Explain the concept of “LEVEL NUMBER” in COBOL.

Answer: The “LEVEL NUMBER” in COBOL indicates the hierarchical level of a data item. It defines whether a data item is elementary (e.g., numeric or alphanumeric) or a group item (e.g., a structure or array).

PART-2

Here’s a list of 50 scenario-based COBOL developer interview questions along with brief sample answers. Remember, in an interview, it’s important to provide clear and detailed explanations to showcase your skills and understanding.

File Processing:

1. Question: How would you read a sequential file and process its records in COBOL?
Answer: I would define a file layout in the Data Division using the FD and 01 level entries. In the Procedure Division, I’d open the file using OPEN statement, read records with READ statement in a loop, and process each record accordingly.

2. Question: Explain how you would handle end-of-file (EOF) while processing records from a file.
Answer: I’d use an EOF condition check after each READ statement, and if EOF is encountered, I would set a flag or condition to exit the loop.

3. Question: If you have multiple record layouts in a single file, how would you differentiate and process them? Answer: I’d use the OCCURS DEPENDING ON clause to determine which record layout to use based on a field’s value. This allows dynamic record processing.

Error Handling:

4. Question: Describe your approach to handling runtime errors in a COBOL program.
Answer: I’d use condition-checking constructs like IF statements, EVALUATE statements, and perform appropriate actions based on the error type, like displaying an error message or terminating the program.

5. Question: What is a COBOL ON EXCEPTION clause used for? Give an example.
Answer: The ON EXCEPTION clause is used to handle specific exception conditions that occur during file operations. For instance, ON EXCEPTION could be used to handle a specific file status code and take appropriate action.

Data Manipulation:

6. Question: How do you perform arithmetic operations on numeric fields in COBOL?
Answer: I’d use arithmetic verbs like ADD, SUBTRACT, MULTIPLY, and DIVIDE to perform calculations on numeric fields.

7. Question: Explain the difference between the MOVE and STRING statements in COBOL.
Answer: MOVE is used to move data from one field to another, while STRING is used to concatenate data from multiple fields into a single field.

Data Validation:

8. Question: How would you validate user input for numeric and alphanumeric fields?
Answer: I’d use COBOL’s condition-checking statements like IF or EVALUATE to validate input against predefined conditions. For numeric fields, I’d ensure they contain only numbers, and for alphanumeric fields, I’d check length and allowed characters.

9. Question: When validating dates, how do you ensure the date entered is valid and in the correct format?
Answer: I’d use COBOL’s date validation functions or perform checks on the numeric values of day, month, and year components to ensure they fall within appropriate ranges.

Sorting and Merging:

10. Question: Describe how you would sort a file using COBOL. Answer: I’d define a sort key using the SORTKEYS clause in the SELECT statement, then use the SORT verb in the Procedure Division to sort the records based on the defined keys.

11. Question: How do you merge two sorted files into a single sorted file in COBOL? Answer: I’d use the MERGE verb, specifying the input files and the output file, along with the appropriate sort keys.

Database Interaction:

12. Question: Explain how you would connect to a relational database and retrieve data using COBOL.
Answer: I’d use embedded SQL within the COBOL program to establish a connection, write SQL queries, and retrieve data using FETCH statements.

13. Question: How do you handle transactions when interacting with a database in COBOL?
Answer: I’d use START TRANSACTION and COMMIT statements around the database operations to ensure data integrity and consistency.

Subprograms and Modules:

14. Question: What is a COBOL subprogram and why would you use one?
Answer: A subprogram is a self-contained module that performs a specific task. I’d use subprograms to encapsulate logic for reusability, maintainability, and to avoid code duplication.

15. Question: Explain the differences between CALL and PERFORM statements in COBOL.
Answer: CALL invokes a separate program or subprogram, while PERFORM executes a paragraph or section within the same program.

COBOL Features:

16. Question: How does COBOL handle binary data and computations?
Answer: COBOL supports binary data storage and arithmetic using the USAGE IS BINARY clause. Binary data is stored in a machine-friendly format and allows efficient numeric calculations.

17. Question: What is the significance of the INITIALIZE verb in COBOL?
Answer: The INITIALIZE verb sets all the data items in a group to their initial values. It’s often used to reset data structures before use.

String Manipulation:

18. Question: How would you search for a substring within a larger string in COBOL?
Answer: I’d use the INSPECT verb with the CONVERTING phrase to replace the target substring with a unique value, then search for that value.

19. Question: Explain how you would concatenate two strings in COBOL.
Answer: I’d use the STRING statement to concatenate multiple fields or literals into a single field.

Report Generation:

20. Question: Describe how you would generate a report in COBOL.
Answer: I’d define a report layout using the FD and 01 level entries, use WRITE statements to populate the fields, and perform page handling using conditional checks.

21. Question: How do you ensure proper alignment and formatting of data in a COBOL report?
Answer: I’d define data fields with appropriate data types and edit masks to ensure proper alignment and formatting when displayed in the report.

Record-Level Processing:

22. Question: Explain the differences between sequential and indexed file processing in COBOL.
Answer: In sequential processing, records are read sequentially from start to end, while indexed processing involves random access to records using an index.

23. Question: How would you update a specific record in an indexed file using COBOL?
Answer: I’d use the READ statement to locate the record, update the necessary fields, and use the REWRITE statement to write the updated record back to the file.

COBOL Debugging:

24. Question: What techniques or tools do you use for debugging COBOL programs?
Answer: I’d use debugging statements like DISPLAY to print variables’ values, and I might use debugging tools provided by COBOL IDEs or debuggers.

25. Question: How do you approach troubleshooting logic errors in a COBOL program?
Answer: I’d review the program’s logic step-by-step, ensuring data flows as expected, and use debugging techniques to identify the point where the logic deviates.

Working with Dates:

26. Question: How would you calculate the difference between two dates in COBOL?
Answer: I’d convert the dates to a common unit (like days) and then subtract them to calculate the difference.

27. Question: Explain how you would validate a date entered by a user to ensure it’s in the correct format.
Answer: I’d use pattern matching with regular expressions to validate the date format (e.g., DD/MM/YYYY) entered by the user.

Data Conversion:

28. Question: How would you convert a numeric value to an alphanumeric value in COBOL?
Answer: I’d use the MOVE statement to convert the numeric value to a character string and assign it to an alphanumeric field.

29. Question: Describe how you would handle data type conversion between numeric and alphanumeric fields. Answer: I’d use the MOVE statement to transfer data between different data types, ensuring that the data is properly formatted.

Reusable Code:

30. Question: Explain how you would encapsulate common functionality using COBOL subprograms.
Answer: I’d identify repetitive logic, create a subprogram to encapsulate it, and then CALL the subprogram from various parts of the program.

31. Question: How do you ensure that changes made to a shared subprogram don’t affect other programs using it? Answer: I’d use version control systems to manage changes and ensure proper testing before applying any updates.

Performance Optimization:

32. Question: What techniques do you use to optimize the performance of COBOL programs? Answer: I’d focus on reducing unnecessary I/O operations, optimizing loop structures, minimizing memory usage, and utilizing appropriate indexing techniques.

33. Question: Explain how you would handle memory management to avoid excessive usage in COBOL. Answer: I’d use appropriate data types and structures, release resources when they are no longer needed, and avoid excessive recursion.

Integration with Modern Technologies:

34. Question: How would you integrate a COBOL program with a web service?
Answer: I’d use technologies like RESTful APIs or SOAP to communicate with the web service, perform data serialization/deserialization, and handle HTTP requests and responses.

35. Question: Describe the process of integrating COBOL programs with modern databases like NoSQL databases. Answer: I’d use appropriate APIs or drivers to connect to the database, convert data between COBOL and database formats, and execute queries.

Data Encryption and Security:

36. Question: How would you implement data encryption in COBOL to secure sensitive information? Answer: I’d use encryption libraries or routines provided by the platform to encrypt and decrypt sensitive data before storing or transmitting it.

37. Question: Explain how you would ensure data security and user authentication in a COBOL application. Answer: I’d implement proper access controls, user authentication mechanisms, and secure communication protocols (such as HTTPS) to protect data and ensure secure interactions.

Batch Processing:

38. Question: Describe the steps you would take to optimize batch processing in COBOL, considering large data sets.
Answer: I’d break down large processes into smaller sub-processes, utilize efficient sorting and indexing techniques, and implement parallel processing when possible.

39. Question: How would you monitor and manage the progress of a batch job in COBOL?
Answer: I’d use job control language (JCL) to define and submit batch jobs, monitor job execution using system logs, and handle job completion or failure scenarios.

Database Migration:

40. Question: Explain the process of migrating data from a legacy mainframe database to a modern relational database.
Answer: I’d extract data from the legacy database, transform it to match the new schema, and then load it into the modern database using ETL (Extract, Transform, Load) processes.

41. Question: What considerations would you take into account when migrating COBOL programs and data from one platform to another?
Answer: I’d consider the differences in platform-specific syntax, data types, and APIs. I’d test thoroughly to ensure compatibility and address any migration-related issues.

Dynamic Memory Allocation:

42. Question: How would you dynamically allocate memory in COBOL programs?
Answer: I’d use the POINTER data type along with the GETMAIN and FREEMAIN functions provided by the system to allocate and release memory dynamically.

43. Question: What precautions would you take to avoid memory leaks in a COBOL program that uses dynamic memory allocation?
Answer: I’d ensure that memory allocated using GETMAIN is eventually released using FREEMAIN, and I’d thoroughly test memory allocation and deallocation routines.

Business Rules and Logic:

44. Question: How would you handle complex business rules that involve multiple conditions and calculations in a COBOL program?
Answer: I’d use conditional statements like IF and EVALUATE to represent different cases and implement the calculations step by step.

45. Question: Explain how you would update a COBOL program to accommodate changes in business rules. Answer: I’d identify the parts of the program affected by the changes, modify the logic as needed, and thoroughly test the program to ensure it works as intended.

Code Documentation:

46. Question: Describe the importance of documenting COBOL programs and how you would approach it.
Answer: Documentation helps other developers understand the program’s functionality. I’d add comments to explain complex logic, variable names, and any external dependencies.

47. Question: What information should be included in COBOL program documentation? Answer: Documentation should include program purpose, input/output details, major data structures, variable descriptions, and any assumptions or special considerations.

Date and Time Handling:

48. Question: How would you handle date and time calculations that involve time zone differences in COBOL?
Answer: I’d use libraries or functions provided by the system to convert date and time values between different time zones, considering daylight saving time adjustments.

49. Question: Explain how you would calculate the current age of a person using their birthdate in COBOL. Answer: I’d subtract the birth year from the current year, considering the month and day to accurately calculate the age.

Error Logging and Reporting:

50. Question: What strategies would you use to log and report errors in a COBOL application?
Answer: I’d implement a centralized error logging mechanism, use meaningful error messages, and log detailed information such as error codes, timestamps, and affected data.

Note: It’s important to be ready to explain your answers in more detail during the interview and provide examples from your experience where relevant.

PART-3

These COBOL interview questions cover various aspects of COBOL programming, including syntax, data handling, file processing, and error handling. Reviewing these questions and answers will help you prepare for your COBOL interview.

1. What is COBOL, and what is its primary use?

Answer: COBOL (Common Business Oriented Language) is a high-level programming language primarily used for business, finance, and administrative systems. It was designed to process large volumes of data efficiently.

2. Who developed COBOL, and when was it first introduced?

Answer: COBOL was developed by a committee of experts and was first introduced in 1959.

3. What are some key features of COBOL?

Answer: Key features of COBOL include:

• English-like syntax
• Record-based data structures
• Strong support for file handling
• Extensive support for decimal arithmetic
• Verbosity (wordy and explicit)

4. How do you declare a variable in COBOL?

Answer: In COBOL, you declare a variable using the PIC (Picture) clause, specifying the data type and size. For example:

01 EMPLOYEE-NAME PIC X(30).

5. What is the significance of the 01 level number in COBOL variable declarations?

Answer: The 01 level number indicates the highest level of data hierarchy in a COBOL program. It represents the main data record or structure.

6. What is the maximum size of a COBOL variable, and how is it determined?

Answer: The maximum size of a COBOL variable is determined by its PIC clause. For example, PIC X(30) allows for a maximum of 30 characters.

7. Explain the difference between COMP and COMP-3 data types in COBOL.

Answer: COMP (Binary) data types in COBOL store binary values, while COMP-3 (Packed Decimal) data types store packed decimal values. Packed decimal uses a nibble (4 bits) for each decimal digit.

8. What is the REDEFINES clause in COBOL used for?

Answer: The REDEFINES clause in COBOL allows one variable to share storage with another variable, essentially treating the same memory location as two different data types.

9. What is the purpose of the OCCURS clause in COBOL?

Answer: The OCCURS clause is used to define arrays in COBOL. It specifies the number of times an element occurs within a data structure.

10. What is a PERFORM statement in COBOL, and how is it used?

Answer: The PERFORM statement in COBOL is used for looping and control flow. It repeats a specified set of statements while a condition is true.

11. Explain the difference between MOVE and MOVE CORRESPONDING statements in COBOL.

Answer: The MOVE statement is used to move data from one variable to another, while the MOVE CORRESPONDING statement is used to move data between corresponding elements of two data structures.

12. What is the purpose of the INITIALIZE statement in COBOL?

Answer: The INITIALIZE statement is used to initialize variables to their default or initial values. It is often used at the beginning of a program to reset variables.

13. How do you read and write records in COBOL programs?

Answer: In COBOL, you use READ and WRITE statements to read input records from files and write output records to files.

14. What is the significance of the FD (File Description) section in COBOL?

Answer: The FD section in COBOL defines the structure and characteristics of input and output files, including their record layouts and file properties.

15. What is a “copybook” in COBOL, and how is it used?

Answer: A copybook is a separate file that contains COBOL variable and record definitions. It is used to share common data structures among multiple COBOL programs, promoting code reuse.

16. How do you handle exceptions and errors in COBOL programs?

Answer: COBOL programs typically use IF statements and conditionals to handle exceptions and errors. Additionally, you can use the ON EXCEPTION clause in some COBOL compilers to specify error-handling routines.

17. Explain the difference between STATIC and DYNAMIC calls in COBOL.

Answer: In COBOL, a STATIC call is a subroutine call resolved at compile time, while a DYNAMIC call is resolved at runtime. Dynamic calls are typically used for invoking subroutines based on user input or conditions.

18. What is the PERFORM UNTIL statement used for in COBOL?

Answer: The PERFORM UNTIL statement in COBOL is used for looping. It repeatedly executes a set of statements until a specified condition becomes true.

19. What is a “level-check” error in COBOL, and how can it be resolved?

Answer: A “level-check” error occurs when data structures in a COBOL program do not match the data structures in the associated input or output files. To resolve it, ensure that the data structures are defined consistently.

20. How can you comment your COBOL code?

Answer: In COBOL, you can use the * character to add comments. Anything after * on a line is treated as a comment and is ignored by the compiler.

21. Explain the difference between MOVE and MOVE TO statements in COBOL.

Answer: In COBOL, MOVE is used to move data from one variable to another, while MOVE TO is used to move data to a specific location within a data structure.

22. What is a “level number” in COBOL, and how is it used?

Answer: A level number is a numeric value assigned to a data item in COBOL to indicate its level of hierarchy within a data structure. Level numbers are used to define the structure of a record or data item.

23. How do you handle decimal arithmetic in COBOL programs?

Answer: COBOL provides special arithmetic operations and data types for decimal arithmetic. The COMPUTE statement is often used for performing decimal calculations.

24. What is the purpose of the EXIT PROGRAM statement in COBOL?

Answer: The EXIT PROGRAM statement in COBOL is used to terminate a COBOL program gracefully and return control to the operating system or calling program.

25. How do you format output in COBOL programs?

Answer: COBOL programs use DISPLAY statements to format and display output on the screen or in files. You can use the FORMAT clause to specify the output format

PART-4 : Scenario Based

These scenario-based COBOL interview questions cover a range of practical situations that COBOL developers may encounter. Understanding these scenarios and how to approach them will help you prepare for your COBOL interview.

Certainly! Here are 100 scenario-based COBOL interview questions and answers to help you prepare for your COBOL interview:

1. Scenario: You are tasked with writing a COBOL program to calculate the total cost of a shopping cart with multiple items, each item having a name, quantity, and price. How would you design the program?

Answer:

• Define a data structure to represent each item (e.g., 01 SHOPPING-ITEM, 05 ITEM-NAME, 05 ITEM-QUANTITY, 05 ITEM-PRICE).
• Use a loop to read each item’s quantity and price and calculate the subtotal for each item.
• Maintain a running total to calculate the total cost.
• Display the total cost at the end of the program.

2. Scenario: You are working on a COBOL program that reads customer data from a file and needs to identify customers with overdue payments based on their payment due dates. How would you implement this in COBOL?

Answer:

• Define a data structure to represent customer records, including payment due dates.
• Use a loop to read customer records from the file.
• Compare the payment due date with the current date to identify overdue payments.
• Display or process the information for overdue customers.

3. Scenario: Your task is to develop a COBOL program that reads a CSV file containing employee data (e.g., name, age, department) and generates an HTML report with this data. How would you approach this task?

Answer:

• Use file handling in COBOL to read the CSV file line by line.
• Parse each line to extract employee data (name, age, department).
• Generate HTML code within the program to format the data.
• Write the HTML code to an output file to create the report.

4. Scenario: You need to create a COBOL program that calculates the monthly loan repayment amount for a given loan amount, interest rate, and loan term. How would you design this program?

Answer:

• Define variables for loan amount, interest rate, loan term, and monthly payment.
• Calculate the monthly interest rate (interest rate divided by 12).
• Use a formula to calculate the monthly payment based on the loan amount, interest rate, and loan term.
• Display the monthly payment.

5. Scenario: You are working on a COBOL program that needs to sort a large dataset of customer records based on customer names in ascending order. How can you implement sorting in COBOL?

Answer:

• Define a data structure for customer records.
• Read all customer records into an array or table.
• Use COBOL’s SORT verb to sort the array/table based on customer names.
• Write the sorted records back to the file or display them as needed.

6. Scenario: Your task is to develop a COBOL program that generates invoices for customers based on their purchase orders. The program should calculate the invoice total, including taxes and discounts. How would you approach this task?

Answer:

• Define data structures for customer information, purchase order details, and invoice data.
• Use file handling to read purchase orders from a file.
• Calculate the invoice total, including item prices, taxes, and discounts.
• Generate invoice records and write them to an output file or display them.

7. Scenario: You need to create a COBOL program that reads data from multiple input files, processes the data, and writes the results to different output files based on specific criteria. How would you design the program?

Answer:

• Define data structures for input records, processing logic, and output records.
• Use file handling to read data from multiple input files.
• Apply processing logic to categorize the data based on criteria.
• Write the categorized data to different output files as needed.

8. Scenario: You are tasked with developing a COBOL program that generates a report summarizing sales data for different products and regions. How would you structure the program to handle this?

Answer:

• Define data structures for sales data, including product IDs, regions, and sales amounts.
• Use file handling to read sales data from a file.
• Aggregate and summarize the sales data based on product and region.
• Generate a report with the summary information and display it or write it to an output file.

9. Scenario: Your organization has a legacy COBOL program that needs to be modernized and integrated with a web application. How would you approach the modernization of the COBOL program?

Answer:

• Evaluate the existing COBOL code to identify the key functionalities and data structures.
• Design APIs or web services to expose the COBOL program’s functionality to the web application.
• Develop a wrapper or bridge that allows the web application to communicate with the COBOL program.
• Gradually replace or enhance the COBOL code with modern technologies while maintaining compatibility with the web application.

10. Scenario: You are responsible for maintaining a COBOL program that generates payroll checks for employees. You need to add a new feature to calculate and display overtime pay for eligible employees. How would you implement this enhancement?

Answer:

• Identify the criteria for overtime eligibility (e.g., hours worked in excess of 40 hours per week).
• Modify the program logic to calculate overtime pay for eligible employees.
• Update the payroll checks to include overtime pay calculations.
• Test the program to ensure accuracy in calculating overtime pay.

PART-5 : Scenario Based

These scenario-based COBOL interview questions cover practical situations where COBOL programming skills are essential. Understanding these scenarios will help you demonstrate your knowledge and problem-solving abilities during your COBOL interview.

1. Scenario: You are tasked with writing a COBOL program to calculate and display the sum of numbers from 1 to 100. How would you approach this task?

Answer: To calculate the sum of numbers from 1 to 100 in COBOL, you can use a loop and an accumulator variable. Here’s a simplified example:

IDENTIFICATION DIVISION.
PROGRAM-ID. SumCalculator.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 Sum PIC 9(9) VALUE 0.
01 Counter PIC 9(3) VALUE 1.

PROCEDURE DIVISION.
PERFORM UNTIL Counter > 100
ADD Counter TO Sum
ADD 1 TO Counter
END-PERFORM.
DISPLAY “The sum is ” Sum.
STOP RUN.

2. Scenario: You need to create a COBOL program to read records from an input file, perform some calculations, and write the results to an output file. How would you design this program?

Answer: To design a COBOL program that reads records from an input file, performs calculations, and writes results to an output file, you would need to:

• Define the file structures in the FILE SECTION using FD entries.
• Open the input and output files using OPEN statements.
• Use READ statements to read records from the input file.
• Perform calculations on the data.
• Use WRITE statements to write results to the output file.
• Close the files using CLOSE statements.

Here’s a simplified example:

IDENTIFICATION DIVISION.
PROGRAM-ID. DataProcessor.
DATA DIVISION.
FILE SECTION.
FD InputFile.
01 InputRecord.
…
FD OutputFile.
01 OutputRecord.
…

WORKING-STORAGE SECTION.
…

PROCEDURE DIVISION.
OPEN INPUT InputFile
OPEN OUTPUT OutputFile

PERFORM UNTIL EOF
READ InputFile
IF NOT EOF
PERFORM Calculate
WRITE OutputRecord
END-IF
END-PERFORM

CLOSE InputFile
CLOSE OutputFile
STOP RUN.

Calculate.
…

3. Scenario: You are working on a payroll processing system in COBOL. Each employee’s record contains various fields, including hours worked and hourly rate. How would you calculate the employee’s weekly pay?

Answer: To calculate an employee’s weekly pay in COBOL, you can multiply the hours worked by the hourly rate. If the employee worked more than 40 hours, you can apply overtime rules, such as paying time-and-a-half for hours over 40. Here’s an example calculation:

cobolCopy code

IDENTIFICATION DIVISION.
PROGRAM-ID. PayrollCalculator.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 Hours-Worked PIC 9(3) VALUE 45.
01 Hourly-Rate PIC 9(5)V99 VALUE 10.50.
01 Weekly-Pay PIC 9(6)V99.

PROCEDURE DIVISION.
IF Hours-Worked <= 40
COMPUTE Weekly-Pay = Hours-Worked * Hourly-Rate
ELSE
COMPUTE Weekly-Pay = (40 * Hourly-Rate) + ((Hours-Worked – 40) * (Hourly-Rate * 1.5))
END-IF.
DISPLAY “Weekly pay: ” Weekly-Pay.
STOP RUN.

4. Scenario: You are tasked with reading a CSV file in COBOL, parsing the data, and storing it in a data structure for further processing. How would you approach this task?

Answer: To read a CSV file in COBOL, you would follow these steps:

1. Define a data structure to hold the parsed data, including fields for each column in the CSV file.
2. Use file handling statements (OPEN, READ, CLOSE) to access the CSV file.
3. Read each line from the file and use STRING or INSPECT statements to split the line into individual fields based on comma separators.
4. Store the parsed data in the defined data structure for further processing.

Here’s a simplified example:

cobolCopy code

IDENTIFICATION DIVISION.
PROGRAM-ID. CSVReader.
DATA DIVISION.
FILE SECTION.
FD CSVFile.
01 CSVRecord PIC X(100).

WORKING-STORAGE SECTION.
01 Employee-Data.
05 Employee-ID PIC X(10).
05 Employee-Name PIC X(30).
05 Salary PIC 9(7)V99.

PROCEDURE DIVISION.
OPEN INPUT CSVFile

PERFORM UNTIL EOF
READ CSVFile
IF NOT EOF
STRING CSVRecord DELIMITED BY ‘,’ INTO Employee-Data
DISPLAY “Employee ID: ” Employee-ID
DISPLAY “Employee Name: ” Employee-Name
DISPLAY “Salary: ” Salary
END-IF
END-PERFORM

CLOSE CSVFile
STOP RUN.

5. Scenario: You are developing a COBOL program to generate reports. How can you control page breaks and pagination in COBOL output?

Answer: To control page breaks and pagination in COBOL output, you can use the PAGE LIMIT clause in the FD entry for the output file. You can specify the maximum number of lines per page, and the system will automatically handle page breaks.

For example:

cobolCopy code

FD OutputFile
RECORDING MODE F
BLOCK CONTAINS 0 RECORDS
LABEL RECORDS STANDARD
VALUE OF FILE-ID IS “REPORT.TXT”
DATA RECORD IS OutputRecord
PAGE LIMIT 60. /* Set maximum lines per page */

6. Scenario: You are developing a COBOL program to process records from a file. If a record contains errors, you want to skip it and continue processing the next record. How can you achieve this?

Answer: To skip records with errors in COBOL, you can use conditional statements and CONTINUE statements. When you encounter a record with errors, you can skip it by using a CONTINUE statement and continue processing the next record.

Here’s an example:

cobolCopy code

IDENTIFICATION DIVISION.
PROGRAM-ID. DataProcessor.
DATA DIVISION.
FILE SECTION.
FD InputFile.
01 InputRecord.
…

WORKING-STORAGE SECTION.
…

PROCEDURE DIVISION.
OPEN INPUT InputFile

PERFORM UNTIL EOF
READ InputFile
IF NOT EOF
IF Record-Contains-Errors
CONTINUE
ELSE
PERFORM Process-Record
END-IF
END-IF
END-PERFORM

CLOSE InputFile
STOP RUN.

Process-Record.
…

7. Scenario: You are working on a COBOL program that generates invoices. Each invoice contains multiple line items. How would you structure the data and code to handle multiple line items efficiently?

Answer: To handle multiple line items efficiently in a COBOL program for generating invoices, you can structure the data using arrays or tables to hold line item details. You would define a data structure to represent a line item and an array or table to store multiple line items for each invoice.

Here’s a simplified example:

cobolCopy code

IDENTIFICATION DIVISION.
PROGRAM-ID. InvoiceGenerator.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 Line-Item OCCURS 100 TIMES.
05 Item-Number PIC 9(5).
05 Description PIC X(50).
05 Quantity PIC 9(3).
05 Unit-Price PIC 9(6)V99.
01 Invoice-Total PIC 9(9)V99 VALUE 0.

PROCEDURE DIVISION.
INITIALIZE Invoice-Total

PERFORM UNTIL No-More-Line-Items
PERFORM Read-Line-Item
IF Item-Number NOT EQUAL TO ZERO
PERFORM Calculate-Line-Item
END-IF
END-PERFORM

PERFORM Print-Invoice
STOP RUN.

Read-Line-Item.
…
Calculate-Line-Item.
…
Print-Invoice.
…

8. Scenario: You are working on a COBOL program that needs to sort a large amount of data. How can you efficiently perform sorting in COBOL?

Answer: To efficiently perform sorting in COBOL, you can use external sorting techniques by writing data to temporary files, sorting those files, and then merging them. You can use the SORT verb in COBOL to sort data efficiently.

Here’s a high-level overview of the process:

1. Read data from the input file and write it to multiple temporary files, each containing a portion of the data.
2. Sort each temporary file independently using the SORT verb.
3. Merge the sorted temporary files into a single output file using a merge algorithm.

9. Scenario: You are tasked with handling date calculations in COBOL, such as calculating the number of days between two dates. How can you approach date calculations in COBOL?

Answer: Date calculations in COBOL often involve manipulating date fields and performing arithmetic operations on them. You can define date fields using suitable data types and use the COMPUTE statement to perform date calculations. COBOL’s intrinsic functions can also be useful for date-related operations.

For example, to calculate the number of days between two dates, you can use a combination of date fields and arithmetic operations. COBOL does not have built-in date subtraction, so you would need to calculate the number of days manually by considering leap years and month lengths.

10. Scenario: You are working on a COBOL program that needs to generate reports with subtotals and totals for different sections of the report. How can you accomplish this?

Answer: To generate reports with subtotals and totals in COBOL, you can use control breaks and accumulators. Control breaks involve monitoring key fields in the data and triggering subtotal and total calculations when specific conditions change. Accumulators are variables that store subtotal and total values, which are then printed in the report.

Here’s a simplified example:

IDENTIFICATION DIVISION.
PROGRAM-ID. ReportGenerator.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 Current-Section PIC X(10).
01 Section-Total PIC 9(7)V99 VALUE 0.
01 Grand-Total PIC 9(7)V99 VALUE 0.

PROCEDURE DIVISION.
OPEN INPUT InputFile

PERFORM UNTIL EOF
READ InputFile
IF NOT EOF
IF Section-Changed
PERFORM Print-Subtotal
PERFORM Reset-Subtotal
END-IF
PERFORM Process-Record
END-IF
END-PERFORM

PERFORM Print-Grand-Total
CLOSE InputFile
STOP RUN.

Print-Subtotal.
…
Reset-Subtotal.
…
Print-Grand-Total.
…