Interview question based on skill :
Take as many assements as you can to improve your validate your skill rating
Total Questions: 20
1. Point out the correct statement :
Correct Answer is : All of the mentioned
2. Point out the wrong statement :
Correct Answer is : vectors provide a convenient way to return the results of a statistical computation
3. What would be the output of the following code ? > x <- vector("list", length = 5) > x
Correct Answer is :
4. Which of the following code snippet will create a vector with NAs in it ?
Correct Answer is : x >- c(1, 2, NA, 10, 3)
5. .What would the following code print ? > x <- c(1, 2, NaN, NA, 4) > is.na(x)
Correct Answer is : FALSE FALSE TRUE TRUE FALSE
6. Point out the wrong statement :
Correct Answer is : is.nan() is used to test objects if they are NA
7. Data frames can be converted to a matrix by calling data._______
Correct Answer is : matrix()
8. What would the following code print ? > x <- data.frame(foo = 1:4, bar = c(T, T, F, F)) > ncol(x)
Correct Answer is : 2
9. Point out the correct statement :
Correct Answer is : All of the mentioned
10. What would be the output of the following code ? > x <- 1:3 > names(x)
Correct Answer is :
11. Which of the following statement changes column name to h and f ?
Correct Answer is : colnames(m) <- c(“h”, “f”)
12. .Which of the following is used for reading tabular data ?
Correct Answer is : read.csv
13. What will be the output of following code snippet ? > lm <- function(x) { x * x } > lm
Correct Answer is : function(x) { x * x }
14. A function, together with an environment, makes up what is called a ______ closure.
Correct Answer is : function
15. Which of the variable in the following code is variable ? > f <- function(x, y) { + x^2 + y / z + }
Correct Answer is : z
16. Point out the wrong statement :
Correct Answer is : The order of the packages on the search list does not matter
17. R uses _________ scoping⁶⁰ or static scoping.
Correct Answer is : lexical
18. The only environment without a parent is the ________ environment.
Correct Answer is : empty
19. The ________ for R are the main feature that make it different from the original S language
Correct Answer is : scoping rules
20. The _________ function is a kind of “constructor function” that can be used to construct other functions.
Correct Answer is : make.power()
