Control Structures In R Programming — Part 2 MCQs with Explanations

Import data is the correct answer to “R Commander is used to . . . . . . . . in R.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

three is the correct answer to “R has . . . . . . . . basic indexing operators.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

for(i in 1:100) { if(i <= 20) { next } } is the correct answer to “Which of the following code skips the first 20 iterations”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Matrix data object is the correct answer to “If the function in a console is.matrix(X) returns true then X can be considered as a . . . . . . . .”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

unclass (as.Date ("2018-12-28")) is the correct answer to “How is a Data object represented internally in R language”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

rbind() is the correct answer to “. . . . . . . . function can be used to add datasets in R provided with the columns in the datasets should be the same.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Lapply is the correct answer to “If the programmers want the output to be a data frame or a vector, then . . . . . . . . function is used.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

apply() is the correct answer to “. . . . . . . . loop over a list and evaluate a function on each element.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Error is the correct answer to “What will be the output of the following R code? > printmessage <- function(x) { + if(x > 0) + print("x is greater than zero") + else + print("x is less than or equal to zero") + invisible(x) + } > printmessage(NA)”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

save (x, file="x.Rdata") is the correct answer to “What is the command used to store R objects in a file”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

> y <- "meat" > switch(y, fruit = "banana", vegetable = "broccoli", "Neither") is the correct answer to “Which of the following R code will print "Neither"”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

rnorm is the correct answer to “. . . . . . . . function generates "n" normal random numbers based on the mean and standard deviation arguments passed to the function.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

$a [1] 1 2 $b [1] 1 2 3 is the correct answer to “What will be the output of the following R code? > x <- list(a = matrix(1:4, 2, 2), b = matrix(1:6, 3, 2)) > lapply(x, function(elt) { elt[,1] })”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Transpose() is the correct answer to “. . . . . . . . is the easiest method for reshaping the data before analysis.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

is.matrix(X) is the correct answer to “. . . . . . . . returns TRUE then X can be termed as a matrix data object.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

R base is the correct answer to “. . . . . . . . package provides basic functionalities in R environment like arithmetic calculations, input/output.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

2.2903605 2.3271663 -0.7060073 1.3622045 -0.2892720 is the correct answer to “What will be the output of the following R code? > x <- 3 > switch(x, 2+2, mean(1:10), rnorm(5))”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

[[1]] [1] 0.02778712 [[2]] [1] 0.5273108 0.8803191 [[3]] [1] 0.37306337 0.04795913 0.13862825 [[4]] [1] 0.3214921 0.1548316 0.1322282 0.2213059 is the correct answer to “What will be the output of the following R code? > x <- 1:4 > lapply(x, runif)”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

[1] "a" [1] "b" [1] "c" [1] "d" is the correct answer to “What will be the output of the following R code? > x <- c("a", "b", "c", "d") > for(i in 1:4) { + ## Print out each element of 'x' + print(x[i]) + }”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Library is the correct answer to “. . . . . . . . function gives an error message if the desired package cannot be loaded.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

$a [1] 3 $b [1] 0.1322028 is the correct answer to “What will be the output of the following R code? > x <- list(a = 1:5, b = rnorm(10)) > lapply(x, mean)”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

if ( statement1 ) { statement2 } else if ( statement3 ) { statement4 } else if ( statement5 ) { statement6 } else statement8 is the correct answer to “Which of the following R code syntax is syntactically valid”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Pairs is the correct answer to “. . . . . . . . function takes various parameters like formula, data, subset, labels, etc.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Objective is the correct answer to “. . . . . . . . functions can be "built which contain all of the necessary data for evaluating the function.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

2 is the correct answer to “How many types of data structures does R language have”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Sys.Date is the correct answer to “To get the current date, the . . . . . . . . function will return a Date object which can be converted to a different class if necessary.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Pairs is the correct answer to “A matrix of scatterplots can be produced using . . . . . . . . function.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

browser() is the correct answer to “. . . . . . . . suspends the execution of a function wherever it is called and puts the function in debug mode.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Z <- (3, 4, 4) is the correct answer to “Two vectors M and N are defined as M <- c(3, 2, 4) and N <- c(1, 2). What will be the output of vector Z that is defined as Z <- M*N.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Function is the correct answer to “A programmer builds a . . . . . . . . to avoid repeating the same task or reduce complexity.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

function (x, f, drop = FALSE, ...) is the correct answer to “Which of the following is valid body of split function”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

tapply() is the correct answer to “Which of the following is apply function in R”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

> f <- function() { + cat("Hello, world!\n") + } > f() is the correct answer to “Which of the following R code will print "Hello, world!"”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

45 is the correct answer to “What will be the output of the following R code snippet? > f <- function(a, b) { + print(a) + print(b) + } > f(45)”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

repeat statement is the correct answer to “The syntax of the repeat loop is . . . . . . . .”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Boxplot() or Text() is the correct answer to “In the base graphics system, which function is used to add elements to a plot”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

x <- runif(1, 0, 10) if(x > 3) { y <- 10 } else { y <- 0 } is the correct answer to “Which of the following R code generate a uniform random number”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Subset() is the correct answer to “Which function is used to select variables and observations from a given dataset”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

Error is the correct answer to “What will be the output of the following R code? > printmessage <- function(x) { + if(x > 0) + print("x is greater than zero") + else + print("x is less than or equal to zero") + invisible(x) + } > printmessage(1)”. This question is standard in competitive examination syllabi for Control Structures In R Programming.

error is the correct answer to “. . . . . . . . is an indication that a fatal problem has occurred and execution of the function stops.”. This question is standard in competitive examination syllabi for Control Structures In R Programming.