Why vectors are the fundamental data structure in R Programming - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a numeric vector with elements 1, 2, and 3.

R Programming

vec <- c([1])

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A"1", "2", "3"

B1, 2, 3

Cc(1, 2, 3)

Dlist(1, 2, 3)

Attempts:

3 left

💡 Hint

Common Mistakes

Putting numbers inside quotes creates a character vector, not numeric.

Using list() creates a list, not a vector.

The c() function combines values into a vector. Using 1, 2, 3 creates a numeric vector.

2fill in blank

medium

Complete the code to get the length of the vector vec.

R Programming

len <- [1](vec)

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Alength

Bcount

Csize

Ddim

Attempts:

3 left

💡 Hint

Common Mistakes

Using dim() returns NULL for vectors.

Using size() or count() are not valid R functions.

The length() function returns the number of elements in a vector.

3fill in blank

hard

Fix the error in the code to access the second element of vector vec.

R Programming

second_element <- vec[1]2

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A[[

B(

C{

D[

Attempts:

3 left

💡 Hint

Common Mistakes

Using double brackets [[ ]] causes errors with vectors.

Using curly braces or parentheses for indexing is invalid.

Use single square brackets [] to access elements of a vector by position.

4fill in blank

hard

Fill both blanks to create a vector of even numbers from 2 to 10.

R Programming

evens <- seq([1], [2], by = 2)

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A2

B1

C10

D12

Attempts:

3 left

💡 Hint

Common Mistakes

Starting at 1 creates odd numbers.

Ending at 12 includes a number beyond 10.

The seq() function creates sequences. Starting at 2 and ending at 10 with step 2 gives even numbers.

5fill in blank

hard

Fill both blanks to create a named vector with scores for Alice and Bob, then access Bob's score.

R Programming

scores <- c(Alice = [1], Bob = [2])
bob_score <- scores"Bob"

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A85

B90

C[

D$

Attempts:

3 left

💡 Hint

Common Mistakes

Using $ to access vector elements causes errors.

Mixing up Alice's and Bob's scores.

Named vectors assign values with names. Use square brackets with the name to access an element.