R interview questions part 16
R interview questions part 16
Take as many assements as you can to improve your validate your skill rating
Total Questions: 20
1. What will be the output of following code ? > f <- function(num) { + hello <- "Hello, world!\n" + for(i in seq_len(num)) { + cat(hello) + } + chars <- nchar(hello) * num + chars + } > meaningoflife <- f(3) > print(meaningoflife)
Correct Answer is : 32
2. What will be the output of following code snippet ? > paste("a", "b", se = ":")
Correct Answer is : none of the mentioned
3. Point out the correct statement :
Correct Answer is : All of the mentioned
4. The __________ function returns a list of all the formal arguments of a function
Correct Answer is : formals()
5. Point out the wrong statement :
Correct Answer is : A formal argument can be a symbol, a statement of the form ‘symbol = expression’, or the special formal argument
6. You can check to see whether an R object is NULL with the _________ function.
Correct Answer is : is.null()
7. Which of the following code will print NULL ?
Correct Answer is : > args(paste)
8. What will be the output of following code ? > f <- function(a, b) { + a^2 + } > f(2)
Correct Answer is : 4
9. What will be the output of following code snippet ? > paste("a", "b", sep = ":")
Correct Answer is : “a:b”
10. What will be the output of following code ? > f <- function(a, b) { + print(a) + print(b) + } > f(45)
Correct Answer is : 45
11. R Commander is used to ___________ in R.
Correct Answer is : Import data
12. 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.
Correct Answer is : Z <- (3, 4, 4)
13. How missing values and impossible values are represented in R language?
Correct Answer is : NA & NAN
14. CRAN package ecosystem has more than ______ packages.
Correct Answer is : 6000
15. Which function in R language is used to find out whether the means of 2 groups are equal to each other or not?
Correct Answer is : t.tests ()
16. How many types of data structures does R language have?
Correct Answer is : 2
17. __________ is the easiest method for reshaping the data before analysis.
Correct Answer is : Transpose()
18. ___________ function is used to apply an expression for a given dataset.
Correct Answer is : With()
19. __________ package is used to speed up data frame management code.
Correct Answer is : Dplyr
20. Which package can be integrated with dplyr for large fast tables?
Correct Answer is : Data.table
