Interview question based on skill :
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Total Questions: 20
1. Point out the correct statement :
Correct Answer is : All of the mentioned
2. What would be the value of following expression ? log(-1)
Correct Answer is : Warning in log(-1): NaNs produced
3. Warnings are generated by the _________ function
Correct Answer is : warning()
4. Point out the correct statement :
Correct Answer is : POSIX represents a portable operating system interface, primarily for UNIX systems
5. What will be the output of the following code ? > printmessage <- function(x) { + if(x > 0) + print("x is greater than zero") + else + print("x is less than or equal to zero") + invisible(x) + } > printmessage(1)
Correct Answer is : Error
6. To get the current date, the _______ function will return a Date object which can be converted to a different class if necessary.
Correct Answer is : Sys.Date
7. Which of the following code represents internal representation of a Date object ?
Correct Answer is : unclass(as.Date(“1970-01-02”))
8. What would be the output of the following code ? > x <- as.Date("1970-01-01") > x
Correct Answer is : “1970-01-01”
9. What would be the output of the following code ? > printmessage <- function(x) { + if(x > 0) + print("x is greater than zero") + else + print("x is less than or equal to zero") + invisible(x) + } > printmessage(NA)
Correct Answer is : Error
10. _________ is an indication that a fatal problem has occurred and execution of the function stops
Correct Answer is : error
11. Point out the correct statement :
Correct Answer is : All of the mentioned
12. What would be the value of following expression ? > log(-2.3)
Correct Answer is : Warning in log(-2.3): NaNs produced
13. Warnings are generated by the _________ function
Correct Answer is : warning()
14. Point out the correct statement :
Correct Answer is : Vectorizing the function can be accomplished easily with the Vectorize() function
15. What will be the output of the following code ? > printmessage <- function(x) { + if(x > 0) + print("x is greater than zero") + else + print("x is less than or equal to zero") + invisible(x) + } > printmessage(1)
Correct Answer is : Error
16. What will be the value of following expression ?
Correct Answer is : Error in log(c(-1, 2)): NaNs produced
17. Which of the following code represents internal representation of a Date object ?
Correct Answer is : unclass(as.Date(“1970-01-02”))
18. What would be the output of the following code ? > printmessage2 <- function(x) { + if(is.na(x)) + print("x is a missing value!") + else if(x > 0) + print("x is greater than zero") + else + print("x is less than or equal to zero") + invisible(x) + } > printmessage2(NA)
Correct Answer is : “x is a missing value!”
19. What would be the output of the following code ? > printmessage <- function(x) { + if(x > 0) + print("x is greater than zero") + else + print("x is less than or equal to zero") + invisible(x) + } > printmessage(NA)
Correct Answer is : Error
20. __________ prints out the function call stack after an error occurs.
Correct Answer is : traceback()
