![\"125](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/10\/r-interview-questions-and-answers-2.jpg\")
<\/a>125 R Interview Questions and Answers For Freshers & Experienced<\/p><\/div>\n
2. Frequently Asked R Interview Questions and Answers<\/h2>\n
Q.1. Explain What is R?\u00a0<\/strong> R Interview Questions and Answers – Q.1<\/p><\/div>\n Q.2. What is GUI in R?<\/strong> R interview Questions and Answers – R Discovery<\/p><\/div>\n Q.6. Why should you adopt R programming language?<\/strong><\/p>\n Why R – R interview Questions and Answers<\/p><\/div>\n Read more reasons to learn R Programming.<\/a> R Interview Questions – R Programming Features<\/p><\/div>\n Q.8. What are the applications of R?<\/strong><\/p>\n R interview Questions and Answers – R Applications<\/p><\/div><\/li>\n<\/ul>\n Learn More R Applications in detail.<\/a> Q.10. Why is R Important?<\/strong> Q.11. Is R is a slow language?<\/strong><\/p>\n Q.12. Explain main features to write R code that runs faster?<\/strong> Q.13. What is SAS and SPSS in R?<\/strong> Q.15. Why is R Good for business?<\/strong><\/p>\n Q.16. What is Visualization in R?<\/strong> b) Programming<\/strong><\/p>\n Q.18. What are statistical and programming features of R?<\/strong><\/p>\n R Interview Questions and answers<\/p><\/div>\n a) Statistical Features-<\/strong><\/p>\n b) Programming Features- <\/strong><\/p>\n Q.19. What are the advantages of R?<\/strong><\/p>\n Advantages of R – R programming interview questions<\/p><\/div>\n Q.20. What are the disadvantages of R?<\/strong><\/p>\n Disadvantages of r – r programming questions and answers<\/p><\/div>\n Q.21. Why R language?<\/strong><\/p>\n Q.22. What is Predictive Analysis in R?<\/strong> Predictive analysis process in R – r language interview questions<\/p><\/div>\n Q.24. What is the need for Predictive Analysis in R?<\/strong><\/p>\n Q.25. What is Descriptive analysis in R?<\/strong> Descriptive analysis methods in R<\/p><\/div>\n Q.27. What is R studio and how to use it?<\/strong> We can also use the console in RStudio. If we click “Run” instead of “Source” user input might not work properly. We can use the R documentation like this: help(function.name).<\/p>\n Learn about R Studio in detail.<\/a> Data Types – R questions and answers<\/p><\/div>\n Q.30. What is the main difference between an Array and a matrix?<\/strong> Learn R Vectors in detail.<\/a> Q.33. What is an Atomic vector and how many types of atomic vectors are present in R?<\/strong> Q.34. What is recycling of elements in an R vector? Give an example.<\/strong> r interview questions – Types of objects<\/p><\/div>\n Q.43. What are R Functions?<\/strong> Q.45. What is function definition?<\/strong> r programming interview questions – Components of R Functions<\/p><\/div>\n Q.47. What are Generic Functions in R?<\/strong>
\nR<\/strong> is a language and environment for statistical computing and graphics. It is an open source programming language. R provides a wide variety of statistical and graphical techniques and is highly extensible. Data miners use it for developing statistical software and data analysis. One of the R\u2019s strengths is the ease with which well-designed publication-quality plots can be produced, including mathematical symbols and formulae where needed. R is available as Free Software under the terms of the Free Software Foundation\u2019s GNU General Public License in source code form. It compiles and runs on a wide variety of UNIX platforms and similar systems (including FreeBSD and Linux), Windows and MacOS. The R command line interface(CLI) consist of a prompt, usually the > character.
\nRead more about R Programming in detail.<\/a><\/p>\n![\"R](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/11\/What-is-R-1.jpg\")
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\nGUI stands for Graphical User Interfaces<\/strong>. R is a command line driven program. The user enters commands at the prompt ( > by default ) and each command is executed one at a time. There have been a number of attempts to create a more graphical interface, ranging from code editors that interact with R, to full-blown GUIs that present the user with menus and dialog boxes.
\nRead more about R Programming in detail.<\/a>
\nQ.3. What is CLI in R?<\/strong>
\nCLI<\/strong> stands for Command Line Interface<\/strong>. In a command line interface, you type commands that you want to execute and press return. For example, if you type the line 2+2 and press the return key, R will give you the result [1] 4
\nQ.4. What is data mining and what data miners do in R?<\/strong>
\nR and Data Mining introduces researchers, post-graduate students, and analysts to data mining using R, a free software environment for statistical computing and graphics.
\nQ.5. Who and When R discovered?<\/strong>
\nR was created by Ross Ihaka and Robert Gentleman at the University of Auckland, New Zealand, and is currently developed by the R Development Core Team, of which Chambers is a member. R is named partly after the first names of the first two R authors and partly as a play on the name of S.The project was conceived in 1992, with an initial version released in 1995 and a stable beta version in 2000.<\/p>\n![\"R](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/11\/R.jpg\")
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\nQ.7. What are programming features of R?<\/strong><\/p>\n\n
\na single unit.<\/li>\n
\nmissing data, etc.<\/li>\n
\ngeneric functions. Procedural programming includes procedure, records, modules, and
\nprocedure calls while object-oriented programming language includes class, objects, and
\nfunctions.<\/li>\n<\/ul>\n![\"R](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/11\/Programming-features-of-R-01.jpg\")
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\nQ.9. Compare R with other technologies.<\/strong><\/p>\n\n
\nR is a leading tool for machine learning<\/strong><\/a>, statistics, and data analysis. It is a programming language. By using R we can create objects, functions, and packages. R language is a platform independent so we can use it on any operating systems. The installation of R is free so we can use it without purchasing a license. R is not only statistic package and is an open source. It means anyone can examine the source code to see what exactly is doing on screen. Anyone can add a feature and fix bugs without waiting for the vendor to do this. Thus, it allows you to integrate with other languages (C, C++). It also enables you to interact with many data sources and statistical packages (SAS, SPSS). R has large growing community of users.<\/p>\nBasic R Interview Questions and Answers<\/h2>\n
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\nunderstanding how R works.<\/li>\n
\nR is a popular statistical software which is famous for the enormous amount of packages. R\u2019s syntax is very flexible with making it convenient at the cost of performance. R is indeed slow compared to many other scripting languages, but there are a few tricks which can make our R code run faster.<\/p>\n\n
\nSAS stands for Statistical Analysis System<\/strong>. It was primarily developed to be able to analyze large quantities of agriculture data while SPSS stands for Statistical Package for the Social Sciences and was developed for the social sciences and was the first statistical programming language for the PC.
\nQ.14. Why is R important for data science?<\/strong><\/p>\n\n
\na language where any type of task can be performed.<\/li>\n<\/ul>\n\n
\nusing R programming as their platform and recruit trained users of R.<\/li>\n<\/ul>\n
\nVisualization is any technique for creating images, diagrams, or animations to communicate a message. Visualization through visual imagery has been an effective way to communicate both abstract and concrete ideas since the dawn of humanity.
\nQ.17. What are R topical programming and statistical relevance?<\/strong>
\na) Statistical<\/strong><\/p>\n\n
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<\/a>R interview Questions For Freshers<\/h2>\n
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\nPredictive analysis is the branch of advanced analysis. It used to make predictions about unknown future events. The Predictive analysis contains data collection, statistics, and deployment. It uses many techniques from data mining, statistics, machine learning and analyzes current data to make predictions about future. It also allows the business users to create Predictive intelligence.
\nLearn about R predictive Analysis in detail.<\/a>
\nQ.23. What is Predictive analysis process in R?<\/strong><\/p>\n\n
![\"Predictive](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/11\/Predictive-analysis-processBlock-diagram.jpg\")
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\nIt does exactly what the name Implies \u201cDescribe\u201d. it allows us to learn from our past and to understand how they might influence future outcomes. The main goal of is to find out the reasons behind previous success or failure in the past. Hence, Most of the social analysis is descriptive analysis. For Example – the company\u2019s production, financials, operations, sales, finance, inventory, and customers.
\nLearn more about R Descriptive Analysis in detail.<\/a>
\nQ.26. What are Descriptive analysis methods in R?<\/strong><\/p>\n\n
![\"Descriptive](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/11\/Descriptive-Analysis-Methods.jpg\")
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\na) USING RSTUDIO<\/strong><\/p>\n\n
\n
\nR also provides a lot of other command line arguments<\/li>\n<\/ul>\n
\nQ.28. What are R data types?<\/strong>
\nIn programming, a data type is a classification that specifies what type of a value variable has. It also describes what type of relational, mathematical and logical operations can apply to it without causing an error. We need to use various variables to store information while doing programming in any programming language. Variables are nothing but reserved memory locations to store values. This means that when we create a variable we reserve some space in memory. The variables are assigned with R-Objects. Thus, the data type of the R-object becomes the data type of the variable.
\nRead about R Data Types in detail.<\/a>
\nQ.29. How many types of data types are provided by R?<\/strong>
\nThere are 5 types of data types present in R:<\/p>\n\n
![\"Data](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/11\/Types-of-Data-Types-Provided-by-R.jpg\")
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\nA matrix is always two dimensional as it has only rows and columns. But an array can be of any number of dimensions and each dimension is a matrix. For example, a 3x3x2 array represents 2 matrices each of dimension 3×3.
\nQ.31. What is R vector?<\/strong>
\nThe basic data structure in R is the vector. It comes in two parts: atomic vectors and lists. They have three common properties:<\/p>\n\n
\nQ.32. How many types of vectors are present in R?<\/strong><\/p>\n\n
\nThe atomic vector is the simplest R data type. Atomic vectors are linear vectors of a single primitive type, like an STL Vector in C++. There are four types of atomic vectors are present in R:<\/p>\n\n
\nWhen two vectors of different length are involved in an operation then the elements of the shorter vector are reused to complete the operation. This is called element recycling.
\nExample –<\/strong> v1 <- c(4,1,0,6) and v2 <- c(2,4) then v1*v2 gives (8,4,0,24). The elements 2 and 4 are repeated.
\nQ.35. What is R lists?<\/strong>
\nLists are the object which Contains elements of different types \u2013 like strings, numbers, vectors and another list inside it. A list can also contain a matrix or a function as its elements. The List is created using list() Function. In other words, a list is a generic vector containing other objects. For Example, The variable x is containing copies of three vectors n, s, b and a numeric value 3.
\nn = c(2, 3, 5)
\ns =\u00a0 c(\u201caa\u201d,\u00a0 \u201cbb\u201d,\u00a0 \u201ccc\u201d,\u00a0 \u201cdd\u201d, \u201cee\u201d )
\nb = c(TRUE,\u00a0 FALSE,\u00a0 TRUE,\u00a0 FALSE,\u00a0 FALSE )
\nx = list( n, s, b, 3)\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0# x contains copies of n, s, b)
\nLearn more about R Lists in detail.<\/a>
\nQ.36. Explain how to create a list in R?<\/strong>
\nCreate a list containing string, numbers, vectors and logical values. For Example:
\n[php]List_data <- list(“Green”, “Yellow”, c(5,6,7), TRUE, 51.2)[\/php]
\nprint(list_data) When we execute the above code, it produces the following result-
\n[php][[1]]
\n[1] \u201cGreen\u201d
\n[[2]]
\n[1] \u201cYellow\u201d
\n[[3]]
\n[1] 5, 6, 7
\n[[4]]
\n[1] TRUE
\n[[5]]
\n[1] 51.2[\/php]
\nQ.37. Explain how to access list elements in R?<\/strong>
\nCreate a list containing a vector, a list and a matrix.
\n[php]list_data <- list(c(“Feb”,”Mar”,”Apr”))
\nlist(“white”,13.4)), matrix(c(3,9,5,1,-2,8), nrow = 2)[\/php]
\nFor Example: Give names to the elements in the list:
\n[php]Names(list_data) <- c(\u201c1 st\u00a0 Quarter\u201d, \u201cA Matrix\u201d, \u201cA Inner list\u201d)[\/php]
\nAccess the first element of the list:
\n[php]print(list_data[1])[\/php]
\nAccess the third element. As it also a list, all its elements will print:
\n[php]Print(list_data[3])[\/php]
\nBy using the name of the element access the list elements:
\n[php]Print(list_data$A Matrix)[\/php]
\nIt will produced the following result after executing the above code:
\n[php]$\u201d1 st \u00a0Quarter\u201d [1] \u201cFeb\u201d, “Mar\u201d, “Apr\u201d
\n$A_Inner_list
\n$A_Inner_list[[1]]
\n[1] \u201cWhite\u201d
\n$A_Inner_list[[2]]
\n[1] 13.4
\n$ \u201cA Matrix\u201d [1]
\n[1]\u00a0 \u00a0[2]\u00a0 \u00a0[3]
\n[1] \u00a0 \u00a0 3 \u00a0 \u00a0 5\u00a0 \u00a0 -2
\n[2] \u00a0 \u00a0 9 \u00a0 \u00a0 1\u00a0 \u00a0 \u00a08[\/php]
\nQ.38. Explain how to manipulate list elements in R?<\/strong>
\nCreate a list containing a vector, a matrix and a list.
\n[php]list_data <- list(c(“Feb”,”Mar”,”Apr”),
\nmatrix(c(3,9,5,1,-2,8), nrow = 2), list(“green”,12.3))[\/php]
\nFor Example:
\nGive names to the elements in the list:
\n[php]names(list_data) <- c(“1st Quarter”, “A_Matrix”, “A Inner list”)[\/php]
\nAdd element at the end of the list:
\n[php]list_data[4] <- “New element”
\nprint(list_data[4])[\/php]
\nRemove the last element:
\n[php]list_data[4] <- NULL\u00a0# Print the 4th Element.print(list_data[4])[\/php]
\nUpdate the 3rd Element:
\n[php]list_data[3] <- “updated element”
\nprint(list_data[3])[\/php]
\nWhen we execute the above code, it produces the following result:
\n[php][[1]]
\n[1] “New element”
\n$NULL
\n$`A Inner list`
\n[1] “updated element”[\/php]
\nQ.39. Explain how to generate lists in R?<\/strong>
\nWe can use a colon to generate a list of numbers. For\u00a0example:
\n[php]-3:3
\n[1] -3 -2 -1 0 1 2 3[\/php]
\nQ.40. Explain how to operate on lists in R?<\/strong>
\nR allows to Operate on all list values at once. For example:
\n[php]c(1,3,5) + 4[\/php]
\nThis and the\u00a0Apply function\u00a0allow you to avoid most for loops.
\n[php][1] 5, 7, 9[\/php]
\nQ.41. Can we update and delete any of the elements in a list?<\/strong>
\nWe can update any of the element but we can delete only the element at the end of the list.
\nQ.42. How many types of object are present In R?<\/strong>
\nThere are 6 types of objects present in R:<\/p>\n\n
![\"r](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/11\/types-of-objects-are-present-in-R.jpg\")
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\nA function is a piece of code written to carry out a specified task. Thus it can or can\u2019t accept arguments or parameters and it can or can\u2019t return one or more values. In R, functions are objects in their own right. Hence, we can work with them exactly the same way we work with any other type of object.
\nlearn more about R Functions in detail.<\/a>
\nQ.44. What are features of R functions?<\/strong>
\nFunction component describes the three main components of a function.<\/p>\n\n
\nthat a function does something before it exists.<\/li>\n<\/ul>\n
\nAn R function is been created using the keyword function. The basic syntax of an R function definition is as follows \u2212
\nfunction_name <- function(arg_1, arg_2, …) {
\nFunction body
\n}
\nQ.46. What are the components of R functions?<\/strong>
\nThe different parts of a function are \u2212<\/p>\n\n
\nargument. Arguments are optional; that is, a function may contain no arguments. Also, arguments can have default values.<\/li>\n![\"r](\"https:\/\/data-flair.training\/blogs\/wp-content\/uploads\/sites\/2\/2017\/11\/Components-of-R-functions-1.jpg\")
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\nR has three object-oriented (OO) systems: [[S3]], [[S4]] and [[R5]]. … A method is a function associated with a particular type of object. S3 implements a style of object-oriented programming called generic-function OO.
\nQ.48. What are R packages?<\/strong>
\nPackages are collections of R functions<\/strong><\/a>, data, and compiled code in a well-defined format. The directory where packages are stored is called the library. R comes with a standard set of packages. Others are available for download and installation. Once installed, they have to be loaded into the session to be used.
\nLearn more about R Packages in detail.<\/a>
\nQ.49. Name the functions which helps in importing data from other applications in R?<\/strong><\/p>\n\n