Week 2

Question 1

Answer 1

‘x’ is a vector of length 10 and ‘if’ can only test a single logical statement.

Question 2

Answer 2

The number 27 is returned

Question 3

Answer 3

f

Question 4

What is an environment in R?

Answer 4

a collection of symbol/value pairs

Question 5

The R language uses what type of scoping rule for resolving free variables?

Answer 5

Lexical scoping

Question 6

How are free variables in R functions resolved?

Answer 6

The values of free variables are searched for in the environment in which the function was defined

Question 7

What is one of the consequences of the scoping rules used in R?

Answer 7

All objects must be stored in memory

Question 8

In R, what is the parent frame?

Answer 8

It is the environment in which a function was called

Question 9

control structures in R allow you to…

Answer 9

control the flow of execution of the program

Question 10

if/else

Answer 10

testing a condition

Question 11

for

Answer 11

execute a loop a fixed number of times

Question 12

while

Answer 12

execute a loop while a condition is true

Question 13

repeat

Answer 13

execute an infinite loop

Question 14

break

Answer 14

break the execution of a loop

Question 15

next

Answer 15

skip an interaction of a loop

Question 16

return

Answer 16

exit a function

Question 17

how to write an if/else statement

Answer 17