R Programming Questions and Answers – Control Structures – 3

This set of R Programming MCQs focuses on “Control Structures – 3”.

1. What will be the output of the following R code?

> x <- 3
> switch(2, 2+2, mean(1:10), rnorm(5))

a) 5
b) 5.5
c) NULL
d) 58
View Answer

2. Point out the correct statement?
a) Statements, such as x<-1:10 or mean(y), can be separated by either a semicolon or a new line
b) Whenever the evaluator is presented with a syntactically complete statement that statement is evaluated and the value returned
c) Computation in R consists of sequentially evaluating statements
d) All of the mentioned
View Answer

3. What will be the output of the following R code?

> x <- 3
> switch(6, 2+2, mean(1:10), rnorm(5))

a) 10
b) 1
c) NULL
d) 5
View Answer

4. What will be the output of the following R code?

> y <- "fruit"
> switch(y, fruit = "banana", vegetable = "broccoli", "Neither")

a) “banana”
b) “Neither”
c) “broccoli”
d) Error
View Answer

5. Point out the correct statement?
a) The next statement causes an exit from the innermost loop that is currently being executed
b) There are two statements that can be used to explicitly control looping
c) The break statement immediately causes control to return to the start of the loop
d) Computation in R consists of sequentially evaluating statements
View Answer

6.What will be the output of the following R code?

> centre <- function(x, type) {
+ switch(type,
+        mean = mean(x),
+        median = median(x),
+        trimmed = mean(x, trim = .1))
+ }
> x <- rcauchy(10)
> centre(x, "mean")

a) 0.8760325
b) 0.5360891
c) 0.6086504
d) gives mean with values depending on rcauchy values
View Answer

7. Which of the following R code will print “Neither”?
a)

> y <- "meat"
> switch(y, fruit = "banana", vegetable = "broccoli", "Neither")

b)

> y <- "brocolli"
> switch(y, fruit = "banana", vegetable = "broccoli", "Neither")

c)

> y <- "banana"
> switch(y, fruit = "banana", vegetable = "broccoli", "Neither")

d)

> y >- "banana"
> y(y, fruit = "banana", vegetable = "broccoli", "Neither")

8. R has ________ basic indexing operators.
a) two
b) three
c) four
d) five
View Answer

9. The syntax of the for loop is?
a)

for ( $name in vector )
statement1

b)

for loop( name in vector )
statement1

c)

for ( name in vector )
statement1

d)

forif loop( name in vector )
statement1

10. Which of the following R code syntax is syntactically valid?
a)

if ( statement1 ) {
    statement2
} else if ( statement3 ) {
    statement4
} else if ( statement5 ) {
    statement6
} else
    statement8

b)

if ( statement1 ) {
    statement2
} elseif ( statement3 ) {
    statement4
} elseif ( statement5 ) {
    statement6
} else
    statement8

c)

if ( statement1 ) {
    statement2
} elseif ( statement3 ) {
    statement4
} else if ( statement5 ) {
    statement6
} else
    statement8

d)

if ( statement1 ) {
    statement2
} else if ( statement5 ) {
    statement6
} else
    statement8

Sanfoundry Global Education & Learning Series – R Programming Language.

Here’s the list of Best Books in R Programming Language.