StreamReader and StreamWriter in C Sharp (C#) - Mini Project: Build & Apply

Reading and Writing Text Files with StreamReader and StreamWriter

📖 Scenario: You are working on a simple note-taking app. You want to save notes to a file and read them back later.

🎯 Goal: Learn how to use StreamWriter to write text to a file and StreamReader to read text from a file in C#.

📋 What You'll Learn

Create a text file with some notes using StreamWriter

Set the file path in a variable

Read the notes back from the file using StreamReader

Print the notes to the console

💡 Why This Matters

🌍 Real World

Reading and writing text files is common in apps that save user data, logs, or configuration settings.

💼 Career

Many programming jobs require working with files to store and retrieve data, making StreamReader and StreamWriter essential tools.

1

Create a file path variable

Create a string variable called filePath and set it to the exact value "notes.txt".

C Sharp (C#)

# Create a string variable called filePath and set it to "notes.txt"
# Your code here

Need a hint?

Use string filePath = "notes.txt"; to set the file path.

2

Write notes to the file using StreamWriter

Use StreamWriter with the variable filePath to write these exact lines to the file:
"Shopping list:"
"- Milk"
"- Bread"
Use a using block to open and close the writer.

C Sharp (C#)

string filePath = "notes.txt";
// Use StreamWriter to write the notes inside a using block
// Your code here

Need a hint?

Use using (var writer = new System.IO.StreamWriter(filePath)) and writer.WriteLine() for each line.

3

Read notes from the file using StreamReader

Use StreamReader with the variable filePath inside a using block to read all lines from the file. Store the result in a string variable called notes using ReadToEnd().

C Sharp (C#)

string filePath = "notes.txt";
using (var writer = new System.IO.StreamWriter(filePath))
{
    writer.WriteLine("Shopping list:");
    writer.WriteLine("- Milk");
    writer.WriteLine("- Bread");
}
// Use StreamReader to read all text from the file into a string variable called notes
// Your code here

Need a hint?

Use using (var reader = new System.IO.StreamReader(filePath)) and notes = reader.ReadToEnd();.

4

Print the notes to the console

Write a Console.WriteLine statement to print the variable notes.

C Sharp (C#)

string filePath = "notes.txt";
using (var writer = new System.IO.StreamWriter(filePath))
{
    writer.WriteLine("Shopping list:");
    writer.WriteLine("- Milk");
    writer.WriteLine("- Bread");
}
string notes;
using (var reader = new System.IO.StreamReader(filePath))
{
    notes = reader.ReadToEnd();
}
// Print the notes variable to the console
// Your code here

Need a hint?

Use Console.WriteLine(notes); to display the notes.