R Programming MCQ Questions with answers and solutions Page 39

Q. How do you remove a column named Income from a data frame named my_data in R?

(A) my_data <- my_data[, -which(names(my_data) == "Income")]
(B) my_data$Income <- NULL
(C) drop_column(my_data, "Income")
(D) remove_col(my_data, "Income")

💬 Discuss

✅ Correct Answer: (B) my_data$Income <- NULL

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. In R, what does the unlist() function do?

(A) Converts a list to a vector
(B) Reverses the order of elements
(C) Creates an unsorted list
(D) Extracts unique elements from a vector

💬 Discuss

✅ Correct Answer: (A) Converts a list to a vector

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. How is a character string converted to a numeric vector in R using the as.numeric() function?

(A) as.numeric("123")
(B) numeric("123")
(C) convert_numeric("123")
(D) to_numeric("123")

💬 Discuss

✅ Correct Answer: (A) as.numeric("123")

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. In R, what is the purpose of the subset() function?

(A) Create a subset of a data frame based on conditions
(B) Generate a summary of a data frame
(C) Filter data based on row and column indices
(D) Extract unique values from a vector using subsetting

💬 Discuss

✅ Correct Answer: (A) Create a subset of a data frame based on conditions

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. How do you add a new row to a data frame named my_data with values "Alice" and 28 for columns Name and Age?

(A) my_data <- rbind(my_data, c("Alice", 28))
(B) my_data <- add_row(my_data, Name = "Alice", Age = 28)
(C) my_data$Name <- "Alice"; my_data$Age <- 28
(D) append_row(my_data, c("Alice", 28))

💬 Discuss

✅ Correct Answer: (B) my_data <- add_row(my_data, Name = "Alice", Age = 28)

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. What function is used to concatenate two vectors in R?

(A) concat()
(B) paste()
(C) c()
(D) combine()

💬 Discuss

✅ Correct Answer: (C) c()

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. In R, what does the slice() function do?

(A) Extracts specific rows from a data frame
(B) Dices a vector into smaller slices
(C) Counts the number of slices in a vector
(D) Slices a data frame into smaller data frames

💬 Discuss

✅ Correct Answer: (A) Extracts specific rows from a data frame

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. How do you create a named numeric vector with values 1, 2, and 3 named "one", "two", and "three" in R?

(A) named_vector <- c(one = 1, two = 2, three = 3)
(B) create_named_vec(1, 2, 3, names = c("one", "two", "three"))
(C) numeric_vector(c(1, 2, 3), names = c("one", "two", "three"))
(D) vec_named(c(1, 2, 3), c("one", "two", "three"))

💬 Discuss

✅ Correct Answer: (D) vec_named(c(1, 2, 3), c("one", "two", "three"))

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. How do you check the structure of a data frame named my_data in R?

(A) struct(my_data)
(B) str(my_data)
(C) structure(my_data)
(D) check_structure(my_data)

💬 Discuss

✅ Correct Answer: (B) str(my_data)

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

Q. In R, what is the purpose of the names() function?

(A) Retrieve the number of elements in an object
(B) Set or retrieve names of an object
(C) Assign names to the elements
(D) Remove names from an object

💬 Discuss

✅ Correct Answer: (C) Assign names to the elements

Published by Mr. Dubey ⭐ 111.42K Points at 21-Apr-2024 10:11 am in R Programming

R Programming MCQs with answers Page - 39

Q. How do you remove a column named Income from a data frame named my_data in R?

Q. In R, what does the unlist() function do?

Q. How is a character string converted to a numeric vector in R using the as.numeric() function?

Q. In R, what is the purpose of the subset() function?

Q. How do you add a new row to a data frame named my_data with values "Alice" and 28 for columns Name and Age?

Q. What function is used to concatenate two vectors in R?

Q. In R, what does the slice() function do?

Q. How do you create a named numeric vector with values 1, 2, and 3 named "one", "two", and "three" in R?

Q. How do you check the structure of a data frame named my_data in R?

Q. In R, what is the purpose of the names() function?

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