Why control flow directs execution in R Programming - Challenge Your Understanding

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this R code with if-else?

Consider the following R code snippet. What will it print?

R Programming

x <- 5
if (x > 3) {
  print("Greater")
} else {
  print("Smaller")
}

A [1] "Smaller"

B Error: object 'x' not found

C [1] "Greater"

D [1] "Equal"

💡 Hint

Check the condition x > 3 and what it evaluates to.

Since x is 5, which is greater than 3, the if block runs and prints "Greater".

❓ Predict Output

intermediate

What does this for loop print in R?

Look at this R code. What will be the output?

R Programming

for (i in 1:3) {
  if (i == 2) next
  print(i)
}

A [1] 2

B

[1] 1
[1] 2
[1] 3

C Error: unexpected symbol in "next print"

D

[1] 1
[1] 3

💡 Hint

The 'next' statement skips the current iteration.

When i is 2, 'next' skips printing 2. So only 1 and 3 are printed.

❓ Predict Output

advanced

What is the output of this nested if-else in R?

Analyze this R code and select the correct output.

R Programming

x <- 0
if (x > 0) {
  print("Positive")
} else if (x == 0) {
  print("Zero")
} else {
  print("Negative")
}

A [1] "Positive"

B [1] "Zero"

C [1] "Negative"

D Error: unexpected 'else' in "} else"

💡 Hint

Check the value of x and which condition matches.

x equals 0, so the else if branch runs and prints "Zero".

❓ Predict Output

advanced

What happens when this R code runs with break inside a while loop?

What will this R code print?

R Programming

i <- 1
while (i <= 5) {
  if (i == 3) break
  print(i)
  i <- i + 1
}

A

[1] 1
[1] 2

B

[1] 1
[1] 2
[1] 3

C [1] 3

D Infinite loop

💡 Hint

The break statement stops the loop when i equals 3.

The loop prints 1 and 2, then breaks when i is 3, so 3 is not printed.

❓ Predict Output

expert

What is the value of x after this R code with nested control flow?

Consider this R code. What is the final value of x?

R Programming

x <- 0
for (i in 1:4) {
  if (i %% 2 == 0) {
    x <- x + i
  } else {
    x <- x - i
  }
}

A 2

B -2

C 0

D 4

💡 Hint

Add or subtract i depending on whether it is even or odd.

For i=1 (odd), x=0-1=-1; i=2 (even), x=-1+2=1; i=3 (odd), x=1-3=-2; i=4 (even), x=-2+4=2.