Vector creation with c() in R Programming - Mini Project: Build & Apply

Vector creation with c()

📖 Scenario: You are helping a small shop owner organize their daily sales data. They want to keep track of the number of items sold each day in a simple list.

🎯 Goal: Create a vector using the c() function in R to store the number of items sold each day for a week.

📋 What You'll Learn

Create a vector called sales with the exact values: 5, 8, 6, 7, 9, 4, 10

Create a variable called days and set it to 7

Use a for loop with variable i to iterate over the sales vector

Calculate the total sales in a variable called total_sales

Print the total sales using print(total_sales)

💡 Why This Matters

🌍 Real World

Tracking daily sales helps shop owners understand their business performance and plan better.

💼 Career

Data analysts and business managers often work with vectors and loops to process and summarize data.

1

Create the sales vector

Create a vector called sales using the c() function with these exact values: 5, 8, 6, 7, 9, 4, 10

R Programming

# Create the sales vector with the exact values
# Your code here

Hint

Use the c() function to combine numbers into a vector.

2

Set the number of days

Create a variable called days and set it to 7

R Programming

sales <- c(5, 8, 6, 7, 9, 4, 10)
# Create the variable days and set it to 7
# Your code here

Hint

Just assign the number 7 to the variable days.

3

Calculate total sales with a loop

Create a variable called total_sales and set it to 0. Then use a for loop with variable i to iterate over the sales vector and add each value to total_sales

R Programming

sales <- c(5, 8, 6, 7, 9, 4, 10)
days <- 7
# Initialize total_sales to 0
# Use a for loop with i to add each sales value to total_sales
# Your code here

Hint

Start with total_sales <- 0. Then use for (i in sales) to loop through each number and add it to total_sales.

4

Print the total sales

Write print(total_sales) to display the total number of items sold in the week

R Programming

sales <- c(5, 8, 6, 7, 9, 4, 10)
days <- 7
total_sales <- 0
for (i in sales) {
  total_sales <- total_sales + i
}
# Print the total_sales
# Your code here

Hint

Use print(total_sales) to show the result.

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