35 Questions and Answers About R Programming for an Interview to Help You Get Ready
As a programmer, you may need to know how to code in the R language, especially if you work with data. In this article, you’ll learn what kinds of questions interviewers ask about the R programming language and how to organize your answers so you can do well in the interview.
What can you expect from an interview for a job as a R programmer?
To get ready for your R programming interview, you should do some research and a test of what you already know. Look at job descriptions for positions that require knowledge of R as a good place to start. The job description for a company should tell you what skills you need to have to do the job well.
When you look for R programming jobs, the first thing you might notice is that there are a lot of them. If you’re interviewing for a job as a programmer analyst, SAS programmer, web developer, software developer, data scientist programmer, or any number of other jobs that require coding, you may be asked R interview questions. This is because people who know how to use this programming language are needed in all areas of IT.
The other skills you’ll need for the job interview is another important thing to know. Companies often look for programmers who can code in many different languages, such as Perl, Ruby, Python, and more.
R interview questions may only take up a small amount of time during a developer interview. So, you should expect that the questions will be technical. They will give you a chance to show what you know, how willing you are to learn, and how well you can think critically.
General questions
Here are some general interview questions you might be asked at a programming job interview:
- How do you keep up with the latest changes in coding?
- What do you like about making software?
- What is the most difficult part of this job?
- Describe your ideal development scenario.
- What can you add to our group?
- Why do you want to get a new job or change careers?
- How much do you want to make?
- What about working for this company makes you want to do it?
- Tell me something about you.
- Are you willing to learn new ways to program if you need to?
Questions about past work and history
These questions test how much you know about programming and how much experience you have:
- Are you certified to use any programming languages?
- How long have you been writing code?
- What do you think are the most important skills a programmer should have?
- How much do you know about the R programming language?
- What other kinds of programming languages do you know?
- Which technical skills are you best at?
- Tell us how comfortable you are talking about hard technical topics.
- Tell me about a programming project you worked on that didn’t go as planned. What went wrong?
- Tell me about a project team you led.
- What is your favorite way to write code, and why?
In-depth questions
Here are 10 detailed questions about your programming skills that you may need to answer in a R programming interview:
- Write a string of code or fix it.
- How can you find the missing value in an array of integers?
- How do you get rid of duplicates in a list?
- How do you print the same character more than once in a string?
- How do you count the number of consonants and vowels in a string?
- How do you find all the different ways a string can be put together?
- How would you put a binary search tree into action?
- How do you use an array to do a binary search?
- How do you use an algorithm for insertion sort?
- How do you put a merge sort algorithm into practice?
Sample answers to the most common R programming interview questions
If you’re going to an interview for a job that requires you to know R, it may not be a big part of the interview, but it’s important to show you have the skills needed for the job. Here are some examples of questions and answers for an interview:
- What’s the difference between R and Python?
- How do you choose the right R package to solve a problem?
- What R packages are used to mine for data?
- Why would you want to use the apply family of functions?
- What are the bad things about using R?
When answering these kinds of technical questions, it’s best to talk from experience if it helps you answer clearly and accurately and shows that you know more about the functions or processes being asked about. In some of the answers below, you’ll see how to use the STAR method to answer interview questions. This method asks you to describe your role in a situation and what happened as a result.
What’s the difference between R and Python?
By giving an answer to this question, you can show that you know the basics of R and Python, which may be important for the job. People often compare these two languages because they are similar in some important ways. For example, Python and R are both important in the field of data science. Python can be used for more things, but R is made to make statistical computing resources.
That’s just one way in which these two languages are alike. A full answer shows that you know more about how each language works technically and what it is used for.
“Python and R are similar in that they can both be used for data science and have useful tools for building models. In general, Python is a more general language that can be used to do statistical computations on data, while R is made specifically for statistical computations. Because of this, R is one of the important languages that data scientists use.
R is a language that was made to help people understand data, so it makes it easier to see data and understand how models work. Python, on the other hand, is a lot easier to learn than R, which has a steep learning curve. They both have strong communities that can help with resources and education.
How do you choose the right R package to solve a problem?
This question gives you the chance to show that you know how to use R by talking about how you choose the right package. It also shows how well you can use critical thinking skills to solve problems. A data scientist can choose from thousands of options in the package repository, so they need to use a method to choose the right one.
If you don’t know how to answer a question about how you do something, you might want to try the STAR method.
Example: “When I worked as a data scientist, I perfected my way of choosing packages because I had to do it so often. First, I choose packages based on what I need for my development. Then I pick out the ones with the best comments. I read the reviews of these packages to find out what other data scientists thought about them and if anyone had used this package for the same reason. If I still have more than one option, I’ll ask the R community what I should do. By doing this every time I put a package into place, I was better able to meet the needs of the company and achieve my professional goals.
What R packages are used to mine for data?
Companies that store and look at a lot of data use a method called “data mining.” It’s a way of analyzing large amounts of data to find the right insights. During a R interview, you will probably be asked how well R helps processes like data mining, which are important for managing and keeping the data that keeps companies competitive.
Other important things about R that have to do with data are:
- Generating visualizations from data
- Using statistics to turn data into conclusions
You should be able to answer any practical questions about how the R language is used to process data.
Some of the packages used for data mining in R are rpart and caret for implementing machine learning models, data table for large files, and GGplot for plotting data visualization.
Why would you want to use the apply family of functions?
This question asks you to talk about the benefit of a certain feature. This shows that you have a deeper understanding of the programming language, and it also lets you talk about a specific part of R that is probably important to the role. In this answer, you can give an example of how you solved a problem using the apply family of functions. Any number of things could be asked the same question, so make sure you study the most important tasks for the role.
Example: “The apply family of functions feature translates to apply(X,MARGIN,FUNCTION…), where X is a data matrix or array, margin is either columns of data, rows of data, or both, and the function decides which formula should be used. This is helpful because it lets you use a function on a large amount of data in an array or matrix without having to do each function separately. It doesn’t take a lot of time or money to get insights from data using R.
I used the apply family of functions a lot when I was a data scientist for QuillCo. One time was when I was asked to predict that sales would go up by 10% every year for three years. Using the apply family of functions, I was able to change all of the year-end sales data in a given matrix to show a 10% increase for each year shown. With this information, important decisions were made about which products’ prices needed to be changed.
What are the bad things about using R?
When you’re asked to name drawbacks, you can show three things. You can use what you already know about R to answer the question correctly, showing that you know how R works in theory. You can also use critical thinking when you want to talk about the bad things. Lastly, you can show that you can easily handle a difficult question that asks you to be critical of something. It’s important to be polite when you bring up these examples.
“The biggest problem with R is that it doesn’t have a lot of security. Because it wasn’t made with security in mind from the start, people who use R need to think about which outside resources are best to keep it safe. Being open source can be a good thing or a bad thing. When it’s seen as a downside, it’s because there’s no governing body to make sure everything is consistent and standardized. Lastly, Python was once thought to be better in terms of memory and speed, but now that 64-bit is available, that’s not really an issue.
