COBOL (Common Business Oriented Language) remains a foundational programming language in the business world, particularly in industries like banking, finance, and government. Whether you’re a seasoned COBOL developer or aspiring to enter the field, preparing for COBOL interviews is essential. In this comprehensive guide, we’ll explore the top 20 COBOL interview questions and provide detailed answers to help you ace your next interview.
COBOL benefits programmers by providing a robust platform for developing and maintaining business-critical applications. Here’s how:
- Accessibility: COBOL’s English-like syntax makes it relatively easy for programmers to learn and understand, especially those with a background in business or finance.
- Robustness: COBOL is designed for handling large-scale transactional operations reliably. Its built-in features for file handling, data manipulation, and arithmetic operations ensure robust program execution.
- Compatibility: Many legacy systems and mainframe environments still rely on COBOL, offering a wealth of job opportunities for programmers with COBOL skills. Additionally, modernization efforts often involve interfacing with existing COBOL code, making it a valuable skillset.
- Stability: COBOL applications are known for their stability and longevity. Once developed and deployed, COBOL programs tend to run for many years without significant changes, providing job security for programmers specializing in COBOL.
- Industry Demand: Despite its age, COBOL remains prevalent in industries such as banking, insurance, and government, where reliability and scalability are paramount. Programmers proficient in COBOL can find lucrative opportunities in these sectors.
Top 20 COBOL Interview Questions and answers
1. What is COBOL, and why is it still relevant today?
- COBOL is a high-level programming language primarily used for business, finance, and administrative systems. Despite being over six decades old, COBOL remains relevant due to its stability, reliability, and extensive use in legacy systems.
2. What are the divisions in a COBOL program?
- COBOL programs are divided into four divisions: Identification Division, Environment Division, Data Division, and Procedure Division. Each division serves a specific purpose, such as identifying the program, defining data structures, and specifying processing logic.
3. Explain the difference between a level-number and a filler in COBOL.
- A level-number indicates the hierarchical structure of data items in the Data Division, while a filler denotes a placeholder or unused area in a data record. Level-numbers range from 01 to 49, indicating data fields, whereas fillers are denoted by level-number 77.
4. What is the significance of the “Picture” clause in COBOL?
- The “Picture” clause defines the format or structure of data items in COBOL. It specifies the type, size, and formatting characteristics of alphanumeric, numeric, and other data types, ensuring proper representation and manipulation of data.
5. How do you perform arithmetic operations in COBOL?
- COBOL provides various arithmetic verbs like ADD, SUBTRACT, MULTIPLY, and DIVIDE for performing arithmetic operations on numeric data items. These verbs adhere to COBOL’s strict data typing rules and handle arithmetic exceptions gracefully.
6. What is the purpose of the “Perform” verb in COBOL?
- The “Perform” verb is used for repetitive execution of sections or paragraphs within a COBOL program. It allows for structured looping and branching based on conditions, enhancing program readability and maintainability.
7. Explain the difference between “Call” and “Perform” in COBOL.
- “Call” is used to invoke separate COBOL programs or subroutines, enabling modularization and code reuse. In contrast, “Perform” is used for repetitive execution of sections or paragraphs within the same program, facilitating structured looping and branching.
8. How do you handle file processing in COBOL?
- COBOL provides file handling verbs like OPEN, READ, WRITE, and CLOSE for sequential and random access file processing. These verbs enable COBOL programs to interact with external files, such as reading input data or writing output records.
9. What are the different file organizations supported in COBOL?
- COBOL supports various file organizations, including sequential, indexed, and relative. Sequential files are accessed sequentially from start to end, indexed files use a key to access records randomly, and relative files access records based on their relative position within the file.
10. How do you handle error conditions in COBOL?
- COBOL provides error handling mechanisms like condition-names, “On” statements, and the “Handle Condition” phrase for graceful error handling. These mechanisms allow COBOL programs to detect and respond to error conditions effectively, ensuring robustness and reliability.