# Frequently Asked R Programming Interview Questions and Answers

## 1. Top R Programming Interview Questions

As we have already discussed too much about **R Programming **interview questions and answers in our previous blogs. So, in this blog, we will be going to provide some tricky R Programming Interview questions. Moreover, these are logical based interview questions and answers. Also, this tutorial contains totally advanced terminologies and singles to long type R Programming Interview questions. This R Programming Interview questions will surely help you to resolve your every single query. And also this R Programming Interview questions will help you in preparations for the interview.

So, let’s explore R Programming Interview Questions.

## 2. 30 Terminologies Based R Programming Interview Questions

Below are some R Programming Interview Questions based on R Terminology –

**Q.1. Explain what is transpose.**

Basically, we use it for reshaping of the data. That further can use for analysis. Also, we can perform transpose by using t() function.

**Read more about transpose in detail**

**Q.2. What is the difference between the data frame and a matrix in R?**

Data frame can contain heterogeneous inputs while a matrix cannot.

**matrix**– store only similar data type

**data frame**– can be different data types like characters, integers or other data frames.

**Read more about Data Frames in R Programming**

**Q.3. What is t-tests() in R?**

We use it to determine that the means of two groups are equal or not by using t.test() function.

**Read more about R Programming t-tests() in detail**

**Q.4. What are co-relations in R?**

We use functions cor() or cor.test() to compute it:

**For Example**:

- cor() computes the correlation coefficient.
- cor.test() test for association/correlation between paired samples.

**Q.5. What is the power analysis?**

We can use it for experimental design. Also, use to determine the effect of given sample size.

**Q.6. What are covariances in R?**

Covariance is a measure of how changes in one variable are associated with changes in a second variable. In general, it measures the degree to which two variables are linearly associated.

**Q.7. What is the use of abline() function?**

abline() function adds the reference line to a graph.

Syntax:-

abline(h=yvalues, v=xvalues)

**Q.8. What is iPlots?**

It is a package which provides bar plots, mosaic plots. Also, it provides box plots, parallel plots, scatters plots and histograms.

**Q.9. What is the of use Matrix package?**

It includes many functions. But it supports only sparse and dense matrices. Such as Lapack, BLAS etc.

**Read more about R matrix in detail**

**Q.10. How can you merge two data frames in R language?**

We can use cbind () functions to merge data frames manually.

**Learn more about R data frames in detail**

**R Programming Interview Questions For Freshers- Q. 1,2,5,6,9,10**

**R Programming Interview Questions For Experience- Q. 3,4,7,8**

**Q.11. Which package provides the bootstrapping?**

Boot Package

**Read more about Bootstrapping in detail**

**Q.12. I have a string “contact@dataflair.com”. Which string function can be used to split the string into two different strings “contact@dataflair” and “com”?**

This can be accomplished using the strsplit function. Also, splits a string based on the identifier given in the function call. Thus, the output of strsplit() function is a list.

strsplit(“contact@dataflair.com”,split = “.”)

Output of the strsplit function is –

## [[1]]
## [1] ” contact@dataflair” “com”

**Q.13. What is the purpose of using Next statement in R language?**

If a developer wants to skip the current iteration of a loop in the code without terminating it then they can use the next statement.

**Learn more about statements in R in detail**

**Q.14. How can you save your data in R?**

To save data in R, there are many ways, but the easiest way of doing this is

Go to Data > Active Data Set > Export Active DataSet and a dialogue box will appear, when you click ok the dialogue box lets you save your data in the usual way.

**Read more about R in detail**

**Q.15. What are applications of Predictive analysis in R?**

**Customer Relationship Management**– it helps to achieve objectives such as customer services, Marketing. Analytic customer relationship management applied throughout the customer lifecycle.**Collection analysis**– Predictive analysis optimizes the collection of allocation resources. Also helps in increasing the recovery and also reducing the collection costs.**Fraud detection**– it can find inaccurate credit applications and identify false claims.**Health Care**– Here it determines the patients who are at risk.

**Learn more about predictive analytics in R in detail**

**Q.16. Explain different types of objects present in R?**

**a. Vectors**

A vector is a sequence of data elements of the same basic type. Hence, Members of a vector called components. Here is a vector containing three numeric values 2, 3 and 5.

**b. Matrices**

It is a collection of numbers. That is arranged into a fixed number of rows and columns. Generally, the numbers are real numbers.

**c. Array**

While matrices confined to two dimensions, arrays can be of any number of dimensions. Arrays are the R data object. And we use this data object to store data in more than two dimensions.

**Read more about R Array in detail**

**d. Lists**

A list is a generic vector containing other objects.

**e. Data frames**

Data frames are tabular data objects. Unlike the matrix in a data frame, each column can contain different modes of data.

**f. Factors**

In R, we store factors as a vector of integer values with a corresponding set of character values to use when the factor displayed. Moreover, we use factor function to create a factor. Therefore, the only required argument to factor is a vector of values which will return as a vector of factor values.

**Read more about R Factor in detail**

**Read more about R in detail**

**Q.17. Explain different types of atomic vectors in R?**

**a. Numeric Data type (12.3, 5, 999)**

Decimal values referred as numeric data types in R. Thus we can assign a decimal value for any variable g like given below, g will become a numeric type.

Ex- g = 53.5 # assign a decimal to g

g # print the variable’s value – g

**b. Integer Data type (2L, 34L, 0L)**

A numeric value with no fraction called integer data, represented by “Int”.

**For Example**:

integer values are -54 and 23. Int size is 2 bytes and long Int size is 4 byte.

Int a: 20

Int b: 30

Int c: 40

**c. Complex Data type (1 + 0i, 1 + 4i)**

With the help of pure imaginary values ‘i”, the value of coding in R can describe.

For Example- k = 1+5i # creating s complex no.

K #printing the value of k

**d. Character Datatype**

The char held as the one-byte integer in memory.

For Example- char grade, symbol;

Grade = “B”

Symbol = “$”

**e. Logical Data type (TRUE, FALSE)**

We use to create it when a comparison between variables done.

Ex- a =3; b =6 #sample values

g = a>b # is a larger than b?

g #print the logical value

**Learn more about R atomic vectors in detail**

**Q.18. Can we update and delete any of the elements in a list?**

We can update any of the element but we can delete only the element at the end of the list.

**Read more about R lists in detail**

**Q.19. Give the command to check if the element 15 is present in vector x.**

15 %in% x

**Read more about vectors in detail**

**Q.20. How do you check if “m” is a matrix data object in R?**

is.matrix(m) should return TRUE.

**R Programming Interview Questions For Freshers- Q. 11,13,14,16,18,19,20**

**R Programming Interview Questions For Experience- Q. 12,15,17**

**Q.21. Vector v is c(1,2,3,4) and list x is list(5:8), what is the output of v*x[[1]]?**

[1] 5 12 21 32s

**Read more about R vectors in detail**

**Q.22. How do you get the standard deviation for a vector x?**

sd(x, na.rm=TRUE)

**Q.23. how to import data into R?**

R has many functions that allow you to import data from other applications.

**Read more how to import data in R in detail**

**Q.24. X is the vector c(5,9.2,3,8.51,NA), What is the output of mean(x)?**

NA

**Q.25. Why is library() function used in R?**

We have already some install packages. Thus, we use this function to show those packages.

**125 Interview Questions and answers for fresher and experienced**

**Q.26. What is the function used for adding datasets in R?**

For adding two datasets rbind() function is used but the column of two datasets must be same. **Syntax**:

rbind(x1,x2……) where x1,x2: vector, matrix, data frames.

Learn more about R in detail.

**Q.27. Define MATLAB package.**

Basically, it includes wrapper functions and variable. Also, these functions are used to replicate Matlab function calls.

**Q.28. Explain what is PDV?**

PDV stands for Program Data Vector. Also, it is the area of memory where data sets are created through SAS system i.e. one at a time. When a program is executed an input buffer is created which will read the data values and make them assign to their respective variables.

** Frequently Asked Interview Questions and Answers**

**Q.29. Explain BOR function?**

Basically, it is a bitwise logical operation. Also, used to return bitwise logical OR between two statements.

**Q.30. How to create axes in the graph?**

Using axes() function custom axes are created.

**R Programming Interview Questions For Freshers- Q. 21,22,23,24,25,26,30**

**R Programming Interview Questions For Experience- Q. 27,28,29**

So, this was all in R Programming Interview Questions. Hope you like this.

## 3. Conclusion – Best R Programming Interview Questions

Hence, in this blog, we have studied top 30 R interview questions. Also, hope these questions will help you to crack the interview. Moreover, this blog also contains links to basic and frequently asked interview questions. Furthermore, If you have any query, fill free to ask in a comment section.