Vector creation with c() in R Programming - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

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

R Programming

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

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

Aseq

Bvector

Clist

Dc

Attempts:

3 left

💡 Hint

Common Mistakes

Using list() instead of c()

Using vector() without specifying type

The c() function combines values into a vector.

2fill in blank

medium

Complete the code to create a character vector with elements "apple", "banana", and "cherry".

R Programming

fruits <- [1]("apple", "banana", "cherry")

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

Ac

Blist

Cvector

Dseq

Attempts:

3 left

💡 Hint

Common Mistakes

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

The c() function creates a vector of characters here.

3fill in blank

hard

Fix the error in the code to create a numeric vector with 4, 5, and 6.

R Programming

numbers <- [1](4, 5, 6)

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

Alist

Bvector

Cc

Dseq

Attempts:

3 left

💡 Hint

Common Mistakes

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

The c() function correctly creates a numeric vector.

4fill in blank

hard

Fill both blanks to create a vector of logical values TRUE and FALSE.

R Programming

logical_vec <- [1](TRUE, [2])

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

Ac

BFALSE

CTRUE

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Using list() instead of c()

Using TRUE twice

The c() function combines logical values TRUE and FALSE into a vector.

5fill in blank

hard

Fill all three blanks to create a vector with elements 10, 20, and 30.

R Programming

vec <- [1]([2], [3], 30)

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

Ac

B10

C20

Dlist

Attempts:

3 left

💡 Hint

Common Mistakes

Using list() instead of c()

Swapping the order of numbers

The c() function combines the numbers 10, 20, and 30 into a vector.

Practice

1. What does the c() function do in R?

easy

A. Reads data from a file

B. Creates a matrix

C. Combines values into a vector

D. Deletes variables

Solution

1. Step 1: Understand the purpose of c()

   The c() function is used to combine multiple values into a single vector in R.

2. Step 2: Compare with other options

   Creating a matrix, deleting variables, or reading files are done by other functions, not c().

3. Final Answer:

   Combines values into a vector -> Option C

4. Quick Check:

   c() = combine values [OK]

Hint: Remember: c() means combine values into one vector [OK]

Common Mistakes:

• Thinking c() creates matrices
• Confusing c() with file reading functions
• Assuming c() deletes variables

2. Which of the following is the correct syntax to create a numeric vector with values 1, 2, and 3 in R?

easy

A. vector(1, 2, 3)

B. c(1, 2, 3)

C. c[1, 2, 3]

D. combine(1, 2, 3)

Solution

1. Step 1: Recall the syntax for vector creation

   In R, c() is used to combine values into a vector, so c(1, 2, 3) is correct.

2. Step 2: Identify incorrect syntax

   vector() is a different function needing length/type, c[] is invalid syntax, and combine() is not an R function.

3. Final Answer:

   c(1, 2, 3) -> Option B

4. Quick Check:

   Correct vector syntax = c(1, 2, 3) [OK]

Hint: Use parentheses with c(), not brackets or other words [OK]

Common Mistakes:

• Using square brackets [] instead of parentheses ()
• Using vector() without proper arguments
• Trying non-existent functions like combine()

3. What is the output of the following R code?

vec <- c(5, 10, 15)
print(vec[2])

medium

A. 10

B. 5

C. 15

D. Error

Solution

1. Step 1: Understand vector indexing in R

   R vectors are 1-indexed, so vec[2] accesses the second element.

2. Step 2: Identify the second element in the vector

   The vector is c(5, 10, 15), so the second element is 10.

3. Final Answer:

   10 -> Option A

4. Quick Check:

   Second element of c(5,10,15) = 10 [OK]

Hint: Remember R starts counting at 1, not 0 [OK]

Common Mistakes:

• Assuming indexing starts at 0
• Confusing element positions
• Expecting an error from valid indexing

4. Identify the error in this R code:

my_vec <- c(1, 2, 3
print(my_vec)

medium

A. Missing closing parenthesis in c()

B. Using print() incorrectly

C. Vector cannot contain numbers

D. Variable name is invalid

Solution

1. Step 1: Check the syntax of c()

   The c() function call is missing a closing parenthesis after the numbers.

2. Step 2: Verify other parts of the code

   The print() function and variable name are correct, and vectors can contain numbers.

3. Final Answer:

   Missing closing parenthesis in c() -> Option A

4. Quick Check:

   Syntax error due to missing ')' [OK]

Hint: Count your parentheses carefully [OK]

Common Mistakes:

• Forgetting to close parentheses
• Thinking print() is wrong
• Believing vectors can't hold numbers

5. You want to create a vector of mixed types: numbers and text, using c(). Which code correctly creates a vector with 10, "apple", and TRUE?

hard

A. c(10 + "apple" + TRUE)

B. c(10; "apple"; TRUE)

C. c(10 "apple" TRUE)

D. c(10, "apple", TRUE)

Solution

1. Step 1: Understand how c() handles mixed types

   The c() function can combine numbers, text, and logical values into a vector, coercing to a common type if needed.

2. Step 2: Check syntax correctness

   c(10, "apple", TRUE) uses commas to separate values correctly. Options A, B, and D use invalid separators or operators.

3. Final Answer:

   c(10, "apple", TRUE) -> Option D

4. Quick Check:

   Correct mixed vector syntax uses commas [OK]

Hint: Separate items with commas inside c() [OK]

Common Mistakes:

• Using semicolons instead of commas
• Trying to add different types with +
• Omitting commas between values