For loop in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print numbers from 1 to 5 using a for loop.

R Programming

for (i in [1]) {
  print(i)
}

Drag options to blanks, or click blank then click option'

Ac(1,5)

B1:5

Cseq(5,1)

Drange(1,5)

Attempts:

3 left

💡 Hint

Common Mistakes

Using c(1,5) which creates a vector with only two elements: 1 and 5.

Using seq(5,1) which counts backwards from 5 to 1.

Using range(1,5) which is not a valid function in R.

The expression 1:5 creates a sequence from 1 to 5 in R, which the for loop iterates over.

2fill in blank

medium

Complete the code to calculate the sum of numbers from 1 to 10 using a for loop.

R Programming

total <- 0
for (num in 1:10) {
  total <- total + [1]
}
print(total)

Drag options to blanks, or click blank then click option'

Anum

Btotal

C1:10

Dsum

Attempts:

3 left

💡 Hint

Common Mistakes

Adding the whole sequence 1:10 instead of the current number.

Adding the total to itself causing incorrect results.

Using sum which is a function, not a variable.

Inside the loop, we add the current number num to the total sum.

3fill in blank

hard

Fix the error in the for loop that prints each letter in the vector letters.

R Programming

letters <- c('a', 'b', 'c')
for ([1] in letters) {
  print(letter)
}

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Ai

Bletters

Cletter

Dl

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different variable name in the loop header and inside the loop.

Using the whole vector as the loop variable.

Using a variable name not defined in the loop.

The loop variable should be letter to match the variable used inside the loop.

4fill in blank

hard

Fill both blanks to create a named vector with squares of numbers greater than 3.

R Programming

nums <- 1:5
squares <- c()
for ([1] in nums) {
  if ([2] > 3) {
    squares[as.character(num)] <- num^2
  }
}

Drag options to blanks, or click blank then click option'

Anum

Bi

Attempts:

3 left

💡 Hint

Common Mistakes

Using the same variable name for both blanks causing confusion.

Using undefined variables in the condition.

Not matching variable names inside the loop.

The loop variable is i, and the condition checks if num is greater than 3.

5fill in blank

hard

Fill all three blanks to create a list of even numbers and their squares from 1 to 6.

R Programming

evens <- list()
for ([1] in 1:6) {
  if ([2] %% 2 == 0) {
    evens[[as.character([3])]] <- [2]^2
  }
}

Drag options to blanks, or click blank then click option'

Anum

Bi

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing variable names causing undefined variable errors.

Using different variables in the condition and list key.

Not using the loop variable consistently.

The loop variable is i, used consistently in the condition and as the list key.