File.open with block (auto-close) in Ruby - Mini Project: Build & Apply

Using File.open with block for auto-closing files

📖 Scenario: You are working on a small program that reads a list of names from a file and processes them safely.

🎯 Goal: Learn how to open a file using File.open with a block so the file automatically closes after reading.

📋 What You'll Learn

Create a text file named names.txt with specific names

Use File.open with a block to read the file

Process the file content inside the block

Print the processed result after reading

💡 Why This Matters

🌍 Real World

Reading and writing files safely is common in many programs, such as loading user data, configuration, or logs.

💼 Career

Knowing how to handle files properly with automatic closing is important for writing reliable Ruby applications and avoiding resource leaks.

1

Create the names.txt file with names

Create a file called names.txt and write these exact names separated by new lines: Alice, Bob, Charlie

Ruby

# Create the file names.txt with the names Alice, Bob, Charlie
# Your code here

Need a hint?

Use File.write to create and write to the file in one step.

2

Set up a variable to hold the names list

Create an empty array called names to store the names read from the file

Ruby

File.write('names.txt', "Alice\nBob\nCharlie\n")

# Create an empty array called names
# Your code here

Need a hint?

Use names = [] to create an empty array.

3

Read the file using File.open with a block and fill names

Use File.open('names.txt', 'r') with a block and inside the block use file.each_line to add each line stripped of whitespace to the names array

Ruby

File.write('names.txt', "Alice\nBob\nCharlie\n")
names = []

# Open 'names.txt' for reading with File.open and a block
# Inside the block, use file.each_line to add each stripped line to names
# Your code here

Need a hint?

Use File.open with a block to ensure the file closes automatically.

4

Print the names array

Write puts names.inspect to display the names array content

Ruby

File.write('names.txt', "Alice\nBob\nCharlie\n")
names = []
File.open('names.txt', 'r') do |file|
  file.each_line do |line|
    names << line.strip
  end
end

# Print the names array
# Your code here

Need a hint?

Use puts names.inspect to print the array in a readable format.