First R program in R Programming - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple R print statement

What is the output of this R code?

print("Hello, R!")

R Programming

print("Hello, R!")

A "Hello, R!"

B Hello, R!

C [1] Hello, R!

D [1] "Hello, R!"

💡 Hint

Remember that print() in R shows the index and quotes for strings.

In R, print() outputs the index [1] and the string with quotes.

❓ Predict Output

intermediate

Value of a variable after assignment

What is the value of variable x after running this code?

x <- 5 + 3 * 2
x

R Programming

x <- 5 + 3 * 2
x

A 11

B 16

C 10

D Error

💡 Hint

Remember the order of operations: multiplication before addition.

3 * 2 = 6, then 5 + 6 = 11, so x is 11.

❓ Predict Output

advanced

Output of a vector creation and print

What is the output of this R code?

v <- c(1, 2, 3, 4)
print(v[2:4])

R Programming

v <- c(1, 2, 3, 4)
print(v[2:4])

A [2] 2 3 4

B [1] 2 3 4

C Error: subscript out of bounds

D [1] 1 2 3

💡 Hint

Indexing in R starts at 1 and 2:4 means elements 2 to 4.

v[2:4] selects elements 2, 3, and 4 which are 2, 3, and 4.

❓ Predict Output

advanced

Output of a conditional statement

What is the output of this R code?

num <- 7
if (num %% 2 == 0) {
  print("Even")
} else {
  print("Odd")
}

R Programming

num <- 7
if (num %% 2 == 0) {
  print("Even")
} else {
  print("Odd")
}

A 7

B [1] "Even"

C [1] "Odd"

D Error: object 'num' not found

💡 Hint

Check if 7 is divisible by 2 with no remainder.

7 %% 2 is 1, so condition is false, else prints "Odd".

❓ Predict Output

expert

Output of a function with recursion

What is the output of this R code?

factorial <- function(n) {
  if (n == 0) return(1)
  else return(n * factorial(n - 1))
}
factorial(4)

R Programming

factorial <- function(n) {
  if (n == 0) return(1)
  else return(n * factorial(n - 1))
}
factorial(4)

A 24

B 10

C Error: recursive call limit reached

D 1

💡 Hint

Factorial of 4 is 4 * 3 * 2 * 1.

factorial(4) = 4 * factorial(3) = 4 * 6 = 24.