Scope of variables in Rust - Mini Project: Build & Apply

Understanding Scope of Variables in Rust

📖 Scenario: Imagine you are organizing a small event and need to keep track of the number of guests in different rooms. You want to understand how variables work inside and outside of blocks in Rust.

🎯 Goal: You will create variables inside and outside blocks to see how their scope affects their accessibility and values.

📋 What You'll Learn

Create a variable called guests with the value 10 outside any block.

Create a block and inside it create a variable called guests with the value 5.

Print the value of guests inside the block.

Print the value of guests outside the block.

💡 Why This Matters

🌍 Real World

Understanding variable scope helps you write clear and bug-free programs by controlling where data can be accessed or changed.

💼 Career

Many programming jobs require knowledge of variable scope to manage memory and avoid errors in complex code.

1

Create the outer variable guests

Create a variable called guests and set it to 10 outside any block.

Rust

# Create a variable called guests and set it to 10
# Your code here

Need a hint?

Use let guests = 10; to create the variable.

2

Create an inner block with a new guests variable

Inside the main function, create a block using curly braces { }. Inside this block, create a new variable called guests and set it to 5.

Rust

fn main() {
    let guests = 10;
    {
        // Create a new variable guests and set it to 5 here
        # Your code here
    }
}

Need a hint?

Use curly braces to create a block and inside it write let guests = 5;.

3

Print the inner guests value inside the block

Inside the inner block, add a println! statement to print the value of guests.

Rust

fn main() {
    let guests = 10;
    {
        let guests = 5;
        // Print the guests variable here
        # Your code here
    }
}

Need a hint?

Use println!("Guests inside block: {}", guests); to print the value.

4

Print the outer guests value outside the block

After the inner block, add a println! statement to print the value of the outer guests variable.

Rust

fn main() {
    let guests = 10;
    {
        let guests = 5;
        println!("Guests inside block: {}", guests);
    }
    // Print the guests variable outside the block here
    # Your code here
}

Need a hint?

Use println!("Guests outside block: {}", guests); after the block to print the outer variable.