Modifying and adding elements in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to change the second element of the vector to 10.

R Programming

vec <- c(1, 2, 3)
vec[[1]] <- 10
vec

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

A2

B3

C1

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Using index 0 which does not exist in R vectors.

Trying to assign value without specifying index.

The second element of the vector is accessed with index 2, so vec[2] <- 10 changes it to 10.

2fill in blank

medium

Complete the code to add the number 4 at the end of the vector.

R Programming

vec <- c(1, 2, 3)
vec <- c(vec, [1])
vec

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

A5

B4

C3

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Adding the number before the vector which changes the order.

Using incorrect syntax like vec + 4 which does not add elements.

Using c(vec, 4) adds 4 to the end of the vector.

3fill in blank

hard

Fix the error in the code to correctly replace the third element with 7.

R Programming

vec <- c(1, 2, 3)
vec[[1]] <- 7
vec

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

A3

B0

C-1

D4

Attempts:

3 left

💡 Hint

Common Mistakes

Using index 0 which is invalid in R.

Using an index larger than the vector length, which adds a new element instead of replacing the third.

The third element is at index 3, so vec[3] <- 7 correctly replaces it.

4fill in blank

hard

Fill both blanks to create a vector with elements 1, 2, 3, and then add 5 at the end.

R Programming

vec <- c([1], [2], 3)
vec <- c(vec, 5)
vec

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

A1

B2

C4

D6

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong numbers for the first two elements.

Forgetting to add 5 at the end.

The vector starts with 1 and 2, then 3 is added. Then 5 is appended at the end.

5fill in blank

hard

Fill all three blanks to create a vector with elements 10, 20, 30, then replace the second element with 25.

R Programming

vec <- c([1], [2], [3])
vec[2] <- 25
vec

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

A10

B20

C30

D25

Attempts:

3 left

💡 Hint

Common Mistakes

Replacing the wrong element.

Using incorrect numbers in the vector.

The vector is created with 10, 20, 30. Then the second element (20) is replaced with 25.