First R program in R Programming - Mini Project: Build & Apply

First R program

📖 Scenario: You want to learn how to write your very first program in R. This program will simply store a message and then show it on the screen.

🎯 Goal: Build a simple R program that stores a greeting message in a variable and then prints it.

📋 What You'll Learn

Create a variable called message with the exact text "Hello, R world!"

Create a variable called exclamation_count and set it to 1

Use a paste0() function to add exclamation_count number of exclamation marks to message

Print the final message using print()

💡 Why This Matters

🌍 Real World

Writing simple scripts to display messages is the first step in learning R programming, useful for data analysis reports and automation.

💼 Career

Basic R programming skills are essential for data analysts and scientists to manipulate data and communicate results.

1

Create the message variable

Create a variable called message and set it to the exact string "Hello, R world!".

R Programming

# Create a variable called message with the text "Hello, R world!"
# Your code here

Hint

Use the assignment operator <- to assign the string to message.

2

Add exclamation count variable

Create a variable called exclamation_count and set it to the number 1.

R Programming

message <- "Hello, R world!"
# Create a variable called exclamation_count and set it to 1
# Your code here

Hint

Use the assignment operator <- to assign the number 1 to exclamation_count.

3

Add exclamation marks to the message

Use the paste0() function to add exclamation_count number of exclamation marks to the end of message. Store the result back in message.

R Programming

message <- "Hello, R world!"
exclamation_count <- 1
# Add exclamation marks to message using paste0() and strrep()
# Your code here

Hint

Use strrep("!", exclamation_count) to repeat the exclamation mark.

4

Print the final message

Print the variable message using the print() function.

R Programming

message <- "Hello, R world!"
exclamation_count <- 1
message <- paste0(message, strrep("!", exclamation_count))
# Print the message
# Your code here

Hint

Use print(message) to show the message on the screen.

Practice

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

easy

A. It saves the text to a file.

B. It displays the text or value inside the parentheses on the screen.

C. It creates a new variable.

D. It deletes existing data.

Solution

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

   The print() function is used to show output on the screen in R.

2. Step 2: Compare options

   Only It displays the text or value inside the parentheses on the screen. correctly describes that print() displays text or values.

3. Final Answer:

   It displays the text or value inside the parentheses on the screen. -> Option B

4. Quick Check:

   print() shows output = It displays the text or value inside the parentheses on the screen. [OK]

Hint: Remember: print() shows output on screen [OK]

Common Mistakes:

• Thinking print() saves to a file
• Confusing print() with variable creation
• Assuming print() deletes data

2. Which of the following is the correct syntax to print the message "Hello, R!" in R?

easy

A. print("Hello, R!")

B. print(Hello, R!)

C. print('Hello, R!)

D. print["Hello, R!"]

Solution

1. Step 1: Check the use of quotes

   Text messages must be inside matching quotes. print("Hello, R!") uses double quotes correctly.

2. Step 2: Verify function syntax

   print() requires parentheses, not square brackets. print("Hello, R!") uses parentheses correctly.

3. Final Answer:

   print("Hello, R!") -> Option A

4. Quick Check:

   Quotes + parentheses correct = print("Hello, R!") [OK]

Hint: Use matching quotes inside print() parentheses [OK]

Common Mistakes:

• Missing quotes around text
• Mismatched or missing closing quotes
• Using square brackets instead of parentheses

3. What will be the output of this R code?

print("Welcome to R programming")

medium

A. [1] "Welcome to R programming"

B. Welcome to R programming

C. Error: unexpected string

D. NULL

Solution

1. Step 1: Understand print() output format in R

   R prints output with an index [1] before the text when printing a character string.

2. Step 2: Match output with options

   [1] "Welcome to R programming" shows the correct R output format including the index.

3. Final Answer:

   [1] "Welcome to R programming" -> Option A

4. Quick Check:

   print() output includes [1] index = [1] "Welcome to R programming" [OK]

Hint: R shows [1] before printed strings [OK]

Common Mistakes:

• Ignoring the [1] index in output
• Expecting plain text without index
• Confusing output with error messages

4. Identify the error in this R code:

print('Hello R)

medium

A. Missing closing parenthesis

B. print() cannot print text

C. Mismatched quotes around text

D. Missing comma inside print

Solution

1. Step 1: Check quotes in the code

   The code starts with a single quote but does not close it properly, causing mismatched quotes.

2. Step 2: Verify parentheses

   The closing parenthesis is present, so the error is not missing parenthesis.

3. Final Answer:

   Mismatched quotes around text -> Option C

4. Quick Check:

   Quotes must match exactly = Mismatched quotes around text [OK]

Hint: Always close quotes properly inside print() [OK]

Common Mistakes:

• Ignoring missing quote errors
• Assuming parentheses are missing
• Thinking print() needs commas inside

5. You want to write a first R program that prints your name and age on separate lines. Which code will do this correctly?

hard

A. print("Name: Alice\nAge: 25")

B. print("Name: Alice")\nprint("Age: 25")

C. print("Name: Alice", "Age: 25")

D. print("Name: Alice")
print("Age: 25")

Solution

1. Step 1: Understand how to print multiple lines in R

   Using two separate print() calls prints on separate lines. The newline character \n inside a single print() prints \n literally, not a new line.

2. Step 2: Check code correctness

   print("Name: Alice") print("Age: 25") correctly uses two print() calls on separate lines with proper syntax.

3. Final Answer:

   print("Name: Alice") print("Age: 25") -> Option D

4. Quick Check:

   Separate print() calls for separate lines = print("Name: Alice") print("Age: 25") [OK]

Hint: Use separate print() calls for multiple lines [OK]

Common Mistakes:

• Using \n inside print() without escape
• Writing \n outside quotes causing syntax error
• Trying to print multiple lines in one print() without proper escape