Data Structures in R Programming MCQ question and answer with solution

1

readlines is used for . . . . . . . .

A) working on data B) reading files C) reading lines in files D) not exist

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Answer & Solution

Answer: Option B

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2

Which of the following R code extracts the second column for the following matrix?

> x <- matrix(1:6, 2, 3)

A) x[2, ] B) x[1, 2] C) x[, 2] D) x[1 1 2]

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Answer & Solution

Answer: Option C

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3

What will be the output of the following R code?

> x <- matrix(1:6, 2, 3)
> x[1, , drop = FALSE]

A) [,1] [,2] [,3]
[1,] 1 3 5 B) [,1] [,2] [,3]
[1,] 2 3 5 C) [,1] [,2] [,3]
[1,] 1 2 5 D) Error

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Answer & Solution

Answer: Option A

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4

The . . . . . . . . operator allows you to string operations in a left-to-right fashion.

A) %>%> B) %>% C) >%>% D) >>>>%%%

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Answer & Solution

Answer: Option B

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5

Point out the correct statement?

A) The complement to the textual format is the binary format B) If you have a lot of objects that you want to save to a file, you can save all objects in your workspace using the save.image() function C) The serialize() function is used to convert individual R objects into a binary format that can be communicated across an arbitrary connection D) All of the mentioned

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Answer & Solution

Answer: Option D

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6

dplyr can be integrated with the . . . . . . . . package for large fast tables.

A) data.table B) read.table C) data.data D) table.read

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Answer & Solution

Answer: Option A

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7

What will be the output of the following R code?

> x <- list(foo = 1:4, bar = 0.6, baz = "hello")
> name <- "foo"
> x$name

A) 1 B) 2 C) 3 D) NULL

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Answer & Solution

Answer: Option D

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8

Point out the wrong statement?

A) When you call unserialize() on an R object, the output will be a raw vector coded in hexadecimal format B) serialize() function is the only way to perfectly represent an R object in an exportable format C) .rda extension is used when save() function is incorporated D) The complement to the textual format is the binary format

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Answer & Solution

Answer: Option A

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9

. . . . . . . . extract a subset of rows from a dataframe based on logical conditions.

A) rename B) filter C) set D) subset

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Answer & Solution

Answer: Option A

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10

Which of the following statement would read file "foo.txt"?

A) data <- read.table("foo.txt") B) read.data <- read.table("foo.txt") C) data <- read.data("foo.txt") D) data <- data("foo.txt")

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Answer & Solution

Answer: Option A

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Data Structures in R Programming MCQ question and answer with solution | R Programming MCQs