R Programming

Which of the following can be used to loop through a vector in R? a) for loop b) while loop c) repeat loop d) All of the above Answer: d) All of the above Explanation: All types of loops (for, while, and repeat) can be used to iterate through a vector in R, depending on […]

What will be the output of the following code? i <- 5; while(i > 0) { print(i); i <- i – 1 } a) 5 4 3 2 1 b) 1 2 3 4 5 c) 1 2 3 4 5 0 d) Error Answer: a) 5 4 3 2 1 Explanation: The while loop

Which of the following loops does not have a conditional check at the start? a) for loop b) while loop c) repeat loop d) do-while loop Answer: c) repeat loop Explanation: The repeat loop does not check any condition at the start; it runs indefinitely until a break statement is used. Reference: R Programming –

Which of the following loops is considered infinite? a) for(i in 1:5) b) repeat { print(1) } c) while(i <= 5) d) None of the above Answer: b) repeat { print(1) } Explanation: The repeat loop will continue indefinitely unless a break statement is encountered, making it an infinite loop. Reference: R Programming – Loops

What will be the output of the following code: for(i in 1:3) { print(i) }? a) 1 2 3 b) 3 2 1 c) Error d) None of the above Answer: a) 1 2 3 Explanation: The for loop iterates through the sequence 1:3 and prints each value (1, 2, and 3). Reference: R Programming

How do you exit a repeat loop in R? a) continue b) break c) stop d) exit Answer: b) break Explanation: The break statement is used to exit a repeat loop in R. Reference: R Programming – Loops MCQ Questions and Answers

Which loop runs at least once, regardless of the condition? a) for loop b) while loop c) repeat loop d) None of the above Answer: c) repeat loop Explanation: The repeat loop runs indefinitely until a break statement is encountered, so it executes at least once. Reference: R Programming – Loops MCQ Questions and Answers

What is the correct syntax for a while loop in R? a) while condition do b) while(condition) c) while condition d) while{condition} Answer: b) while(condition) Explanation: The correct syntax for a while loop in R is while(condition), where the condition is checked before each iteration. Reference: R Programming – Loops MCQ Questions and Answers

What is the default increment step in a for loop in R? a) 1 b) 2 c) 5 d) 0 Answer: a) 1 Explanation: In R, the for loop increments by 1 by default when iterating over a sequence like 1:5. Reference: R Programming – Loops MCQ Questions and Answers

What is the purpose of the next statement in R loops? a) Terminates the loop b) Skips the current iteration and moves to the next c) Pauses the loop d) Repeats the current iteration Answer: b) Skips the current iteration and moves to the next Explanation: The next statement skips the current iteration of the

Which of the following loops will run indefinitely unless manually stopped? a) while(TRUE) b) for(i in 1:5) c) while(i == 0) d) for(i in 1:100) Answer: a) while(TRUE) Explanation: The while(TRUE) loop runs indefinitely since the condition always evaluates to true. It needs a break statement to stop it. Reference: R Programming – Loops MCQ

What is the purpose of the break statement in loops? a) Skips the current iteration b) Exits the loop immediately c) Restarts the loop d) Pauses the loop Answer: b) Exits the loop immediately Explanation: The break statement is used to exit the loop immediately, regardless of the loop’s condition. Reference: R Programming – Loops

Which loop should be used when the number of iterations is not known beforehand? a) while loop b) for loop c) repeat loop d) do-while loop Answer: a) while loop Explanation: The while loop is used when the number of iterations is not known beforehand. It continues until the condition becomes false. Reference: R Programming

What is the correct syntax for a for loop in R? a) for(i = 1; i <= 5; i++) b) for(i in 1:5) c) for i in 1:5 d) for(i, 1:5) Answer: b) for(i in 1:5) Explanation: The correct syntax for a for loop in R is for(i in 1:5), where i takes values from

Which loop in R is used when the number of iterations is known beforehand? a) while loop b) repeat loop c) for loop d) do-while loop Answer: c) for loop Explanation: The for loop is used in R when the number of iterations is known before the loop starts. Reference: R Programming – Loops MCQ

How do you remove NA values from a vector in R? a) remove_na() b) rm.na() c) na.omit() d) delete_na() Answer: c) na.omit() Explanation: The na.omit() function removes NA values from a vector or data set in R. Reference: R Programming – Functions MCQ Questions and Answers

What does the lapply() function do in R? a) Applies a function to each element of a list and returns a list b) Applies a function to a matrix c) Sorts a list d) None of the above Answer: a) Applies a function to each element of a list and returns a list Explanation: The

Which function in R combines multiple vectors into a data frame? a) rbind() b) merge() c) data.frame() d) cbind() Answer: c) data.frame() Explanation: The data.frame() function is used to combine multiple vectors into a data frame in R. Reference: R Programming – Functions MCQ Questions and Answers

What does the apply() function do in R? a) Applies a function over rows or columns of an array or matrix b) Removes missing values from a vector c) Sorts a vector d) Combines two vectors Answer: a) Applies a function over rows or columns of an array or matrix Explanation: The apply() function applies

Which of the following functions returns the maximum value in a vector? a) min() b) max() c) range() d) summary() Answer: b) max() Explanation: The max() function returns the largest value from a given vector. Reference: R Programming – Functions MCQ Questions and Answers

What is the purpose of the str() function in R? a) Converts a value to a string b) Extracts a substring c) Displays the internal structure of an object d) Joins two strings together Answer: c) Displays the internal structure of an object Explanation: The str() function in R displays the internal structure of an

What does the rep() function do in R? a) Repeats a value or vector b) Returns the average of a vector c) Removes duplicates from a vector d) Returns the reverse of a vector Answer: a) Repeats a value or vector Explanation: The rep() function repeats a value or a vector a specified number of

How can you pass multiple arguments to a function in R? a) Using a list b) Using the c() function c) Passing them as individual parameters d) Using a matrix Answer: c) Passing them as individual parameters Explanation: Multiple arguments are passed to a function by specifying them individually, separated by commas, in the function

What does the sum() function do in R? a) Finds the average of numbers b) Finds the sum of numbers c) Finds the difference between numbers d) None of the above Answer: b) Finds the sum of numbers Explanation: The sum() function in R returns the total sum of all the elements in a vector.

How do you define a function with a default argument in R? a) function_name <- function(x = 5) b) function_name <- function(x <- 5) c) function_name <- def(x = 5) d) func function_name(x = 5) Answer: a) function_name <- function(x = 5) Explanation: In R, a default argument is set using the syntax function_name <-