A Guide to COBOL Interview Questions (With Example Answers)

By Indeed Editorial Team

Published November 6, 2022

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

When you have an upcoming job interview, it's helpful to prepare for questions they may ask you in advance. Anticipating the questions and considering how you can discuss your most notable skills and experiences in your responses can help you impress the hiring manager. If you're interviewing for a job in a field related to coding or computer programming, it may be useful to feel ready to answer questions about COBOL. In this article, we discuss COBOL interview questions, examine why employers ask them, provide some possible COBOL questions and example answers, and list some other interview question topics you may hear when applying for programming roles.

COBOL interview questions with sample answers

When preparing answers for COBOL interview questions, it can be helpful to consider what an interviewer hopes to learn about you and why. You can also think about how you might answer these questions to respond confidently. Here's a list of COBOL questions you might encounter in an interview, each with an explanation and sample response:

1. Tell me what you know about COBOL.

This is a broad, open-ended question that an interviewer might use as a starting point to establish your overall understanding of COBOL and or level of experience. They might base their subsequent questions on your response. Even with minimal experience using COBOL, you can prepare yourself to explain what the acronym means and what you know about its applications. Your answer can include the amount of experience you have and highlight any formal training.

Example answer: "COBOL is an acronym for Common Business-Oriented Language. It's an older computer programming language that uses an English-based syntax. It appears in some mainframe computer applications and was previously a popular programming language for various business apps."

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2. What data types are available in COBOL?

This question tests your basic knowledge of COBOL. Your answer can help them understand whether you have direct experience with COBOL or knowledge of its uses. You can comfortably provide a solid answer to this question by knowing the three types of data: alpha-numeric, alphabetic, and numeric. Given that this is a direct question, it's unnecessary to provide a lengthy answer unless the interviewer prompts you.

Example answer: "There are four data types available in COBOL. Alphabetic comprises only letters, and numeric includes numbers only. Then, alphanumeric includes both numbers and letters, and signed includes numbers and integer signs."

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3. What are the primary features of COBOL?

You can further demonstrate your knowledge of this programming language by commenting on features you like. It's typically a good idea to mention the features you are most familiar with so that you can explain each one if the interviewer requests an explanation. You can also use this opportunity to discuss how you used COBOL in previous roles to highlight your transferrable skills.

Example answer: "COBOL is structured in an object-oriented manner, is procedural, and imperative. The features I find most helpful include its portability and many debugging tools. I used COBOL frequently in my previous role where I was upgrading a company's old software applications, which primarily still used this language."

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4. What's the difference between a section and a paragraph?

An interviewer might ask this as part of a series of questions to determine your familiarity with the language. The job role you're applying for likely requires COBOL's use if an interviewer asks multiple questions about it. A high level of COBOL efficiency is likely unnecessary if all the questions are relatively simple and pertain to basic concepts, such as those in the previous examples. Instead, they may be looking for a basic understanding and the ability to learn.

Example answer: "A section consists of two or more paragraphs, meaning that when you perform a section, you automatically execute the subordinate paragraphs. Paragraphs contain sentences which consist of phrases. When you perform a paragraph, you also automatically perform the subordinate sentences and phrases, but you don't affect the section."

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5. What are the main advantages and disadvantages of COBOL?

You can use your answer to this question to demonstrate your level of COBOL experience. Hiring managers may use this type of question to discern which candidates have direct experience with the programming language. If you're familiar with COBOL and you use it often, it can be valuable to mention specific advantages and disadvantages and relate them to your experience. If you don't have much experience, you can list some of the well-known advantages, such as its readability, simplicity, and portability. This may also be an opportunity to compare it to a language you prefer.

Example answer: "COBOL has many advantages, including being easy to learn and compatible with a variety of systems. It's also impressively scalable, which I found very helpful when working on my most recent project. The most significant disadvantage I've encountered with COBOL is it is not as popular as other more modern languages, which can be an issue when collaborating.

"Fortunately, my extensive experience with it makes it easy to share my knowledge with other people on my team. I led a team of five other programmers in my previous role and found it easy to explain how to use COBOL to the team members who weren't familiar with it."

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7. What COBOL verb do you use when updating a file?

An interviewer may use this question to assess your working knowledge of COBOL. How comfortable you are in answering this and similar questions can indicate how extensively you've used the language in the past. You can further demonstrate your knowledge by including some additional details in your answer and explaining how you used these verbs in previous roles.

Example answer: "When updating a file, you use the verb ‘rewrite.' This function overwrites the previous record and can work after completing a successful read operation. It's also important to ensure you open the file in I-O mode when you use this verb."

8. Can you perform a search on an unindexed table?

An interviewer might use a question like this if they want to ensure that you have a strong understanding of and experience using COBOL. Here, it's a good idea to include more detail in your answer to demonstrate the depth of your understanding. For example, you can add detail by explaining why you can't search an unindexed table.

Example answer: "No. You can only search a table after indexing it because you have not determined the order of the rows. Indexing shows the displacement of each element."

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9. How is a static call different from a dynamic call?

This question serves to evaluate whether you understand some of the more complex aspects of COBOL. An interviewer might use this question to distinguish whether you can use COBOL proficiently without significant training. When answering this type of question, it's typically a good idea to define both terms and identify the key differences. A clear and concise answer is usually the best choice for a question like this.

Example answer: "A static call works for a standalone program. This means that you can execute it. A dynamic call applies to a program that you can't execute on its own."

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10. What access modes might you use with the START statement?

This question tests your more advanced understanding and expertise using COBOL. An interviewer might ask this type of question if the role requires you to use COBOL regularly. When providing your answer, consider not only providing the names of the modes but also some details on how to use each one and why.

Example answer: "There are two different access modes for the START statement. One is sequential, and the other is dynamic. Sequential access allows you to access records one at a time in a given order, while dynamic access allows you to skip between records."

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