Interview question based on skill :
Take as many assements as you can to improve your validate your skill rating
Total Questions: 20
1. .rda extension used when saving data with function __________
Correct Answer is : save and save.image functions
2. .RData extension used when we save data using the functions ___________
Correct Answer is : save and save.image functions
3. When you call serialize() on an R object, the output will be ____ coded in hexadecimal format.
Correct Answer is : raw vector
4. The benefit of the _____ function is that it is the only way to perfectly repressed an R object in an exportable format, without losing precision or any metadata.
Correct Answer is : serialize()
5. load() is used for _______
Correct Answer is : reading
6. readlines is used for ____________
Correct Answer is : reading files
7. Which of the following is example of vectorized operation as far as subtraction is concerned ? > x <- 1:4 > y <- 6:9
Correct Answer is : x-y
8. Point out the wrong statement :
Correct Answer is : Very less operations in R are vectorized
9. What would be the output of the following code ? > x <- 1:4 > y <- 6:9 > z <- x + y > z
Correct Answer is : 7 9 11 13
10. What would be the output of the following code ? > x <- 1:4 > x > 2
Correct Answer is : FALSE FALSE TRUE TRUE
11. What would be the output of the following code ? > x <- 1:4 > y <- 6:9 > x/y
Correct Answer is : 0.1666667 0.2857143 0.3750000 0.4444444
12. Which of the following code represents internal representation of a Date object ?
Correct Answer is : unclass(as.Date(“1970-01-02”))
13. What would be the output of the following code ? > x <- as.Date("1970-01-01") > x
Correct Answer is : “1970-01-01”
14. What would be the output of the following code ? > x <- Sys.time() > class(x)
Correct Answer is : “POSIXct” “POSIXt”
15. Which of the following function gives the day of the week?
Correct Answer is : weekdays
16. Point out the correct statement :
Correct Answer is : All of the mentioned
17. What would be the output of the following code ? > p <- as.POSIXlt(x) > names(unclass(p)) > p$wday
Correct Answer is : 1
18. What would be the output of the following code ? > datestring <- c("January 10, 2012 10:40", "December 9, 2011 9:10") > x <- strptime(datestring, "%B %d, %Y %H:%M") > x
Correct Answer is : “2012-01-10 10:40:00 EST” “2011-12-09 09:10:00 EST”
19. Point out the wrong statement :
Correct Answer is : None of the mentioned
20. What would be the output of the following code ? > x <- as.Date("2012-01-01") > y <- strptime("9 Jan 2011 11:34:21", "%d %b %Y %H:%M:%S") > x-y
Correct Answer is : Warning
