R Programming

What is the output of mean(c(2, 4, 6))? a) 4 b) 6 c) 2 d) 5 Answer: a) 4 Explanation: The mean() function calculates the average of a numeric vector. The mean of c(2, 4, 6) is 4. Reference: R Programming – Functions MCQ Questions and Answers

What does the return() function do in R? a) Ends a function and returns a value b) Prints a message c) Stops a script d) None of the above Answer: a) Ends a function and returns a value Explanation: The return() function in R is used to return a value from a function and end

Which function in R returns the number of rows in a data frame? a) ncol() b) length() c) nrow() d) count() Answer: c) nrow() Explanation: The nrow() function returns the number of rows in a data frame or matrix. Reference: R Programming – Functions MCQ Questions and Answers

How do you call a function in R? a) call function_name() b) function_name() c) run function_name() d) execute function_name() Answer: b) function_name() Explanation: To call a function in R, you simply use the syntax function_name(). Reference: R Programming – Functions MCQ Questions and Answers

How do you define a function in R? a) function_name <- function() b) function function_name() c) def function_name() d) func function_name() Answer: a) function_name <- function() Explanation: In R, a function is defined using the syntax function_name <- function(), where function() contains the function logic. Reference: R Programming – Functions MCQ Questions and Answers

Which operator is used to check if a value is less than or equal to another value in R? a) < b) == c) <= d) >= Answer: c) <= Explanation: The <= operator checks if a value is less than or equal to another value in R. Reference: R Programming – Operators MCQ Questions

What does the operator ! do in R? a) Negates a logical value b) Performs logical AND c) Multiplies two numbers d) Divides two numbers Answer: a) Negates a logical value Explanation: The ! operator in R is a logical negation operator, reversing the logical value. Reference: R Programming – Operators MCQ Questions and Answers

What is the result of the expression 6 %/% 4 in R? a) 2 b) 1 c) 3 d) 4 Answer: b) 1 Explanation: The %/% operator performs integer division, so 6 %/% 4 results in 1 (as the remainder is discarded). Reference: R Programming – Operators MCQ Questions and Answers

How do you assign a value to a variable in R? a) == b) = c) ← d) → Answer: c) ← Explanation: The ← operator is the most common way to assign a value to a variable in R. Reference: R Programming – Operators MCQ Questions and Answers

Which of the following is the correct operator for integer division in R? a) %/% b) %% c) // d) ˆ Answer: a) %/% Explanation: The %/% operator in R performs integer division, returning the quotient of the division. Reference: R Programming – Operators MCQ Questions and Answers

What is the difference between && and & in R? a) Both are the same b) && is for element-wise comparison, and & is for logical AND c) & is for element-wise comparison, and && is for logical AND d) && is faster than & Answer: c) & is for element-wise comparison, and && is

What does the operator || do in R? a) Logical OR with element-wise comparison b) Logical AND c) Logical OR with short-circuiting d) Logical XOR Answer: c) Logical OR with short-circuiting Explanation: The || operator is a logical OR operator in R with short-circuiting, meaning it evaluates only the first element of the condition. Reference:

What is the result of 3ˆ2 in R? a) 9 b) 6 c) 8 d) 12 Answer: a) 9 Explanation: The ˆ operator raises 3 to the power of 2, resulting in 9. Reference: R Programming – Operators MCQ Questions and Answers

What does the %% operator do in R? a) Integer division b) Modulus (remainder) c) Exponentiation d) Multiplication Answer: b) Modulus (remainder) Explanation: The %% operator returns the remainder of the division in R. Reference: R Programming – Operators MCQ Questions and Answers

Which of the following is a logical operator in R? a) * b) | c) == d) %/% Answer: b) | Explanation: The | operator is a logical operator used for OR operations in R. Reference: R Programming – Operators MCQ Questions and Answers

How do you check if two variables are not equal in R? a) != b) == c) | d) && Answer: a) != Explanation: The != operator checks if two variables are not equal in R. Reference: R Programming – Operators MCQ Questions and Answers

Which operator is used to raise a number to a power in R? a) ˆ b) %/% c) * d) + Answer: a) ˆ Explanation: The ˆ operator is used in R to raise a number to the power of another number. Reference: R Programming – Operators MCQ Questions and Answers

What is the result of the expression 5 %% 2 in R? a) 1 b) 0 c) 2 d) 5 Answer: a) 1 Explanation: The %% operator returns the remainder of the division, so 5 %% 2 equals 1. Reference: R Programming – Operators MCQ Questions and Answers

Which of the following is a relational operator in R? a) + b) == c) %% d) ˆ Answer: b) == Explanation: The == operator checks if two values are equal, making it a relational operator in R. Reference: R Programming – Operators MCQ Questions and Answers

Which of the following is an arithmetic operator in R? a) == b) * c) && d) | Answer: b) * Explanation: The * operator is used for multiplication, which is an arithmetic operation in R. Reference: R Programming – Operators MCQ Questions and Answers

How do you convert a numeric value to a string in R? a) as.numeric() b) as.character() c) numToString() d) str_numeric() Answer: b) as.character() Explanation: The as.character() function is used to convert a numeric value into a string in R. Reference: R Programming – String MCQ Questions and Answers

Which function in R converts a string to a raw vector? a) rawToChar() b) charToRaw() c) str_raw() d) raw_vector() Answer: b) charToRaw() Explanation: The charToRaw() function converts a character string into a raw vector in R. Reference: R Programming – String MCQ Questions and Answers

How do you reverse the characters in a string in R? a) reverse() b) rev_string() c) str_reverse() d) rev() Answer: c) str_reverse() Explanation: The str_reverse() function reverses the order of characters in a string. Reference: R Programming – String MCQ Questions and Answers

What is the output of the expression nchar("Data")? a) 4 b) 3 c) 5 d) 2 Answer: a) 4 Explanation: The nchar() function returns the length of the string, which is 4 in this case. Reference: R Programming – String MCQ Questions and Answers

How do you detect if a string starts with a specific substring in R? a) str_starts() b) startsWith() c) start_string() d) begins() Answer: b) startsWith() Explanation: The startsWith() function checks if a string starts with a given substring in R. Reference: R Programming – String MCQ Questions and Answers