If–else expression in Rust - Mini Project: Build & Apply

Using If-else Expression in Rust

📖 Scenario: You are creating a simple program that decides if a number is positive or not. This is like checking if the temperature is above zero to decide if you need a jacket.

🎯 Goal: Build a Rust program that uses an if-else expression to check if a number is positive and prints the result.

📋 What You'll Learn

Create a variable called number with the value 10

Create a variable called result that uses an if-else expression to check if number is greater than 0

If number is greater than 0, result should be the string "Positive"

Otherwise, result should be the string "Not positive"

Print the value of result

💡 Why This Matters

🌍 Real World

If-else expressions are used in many programs to make decisions, like checking if a user is logged in or if a payment is successful.

💼 Career

Understanding if-else expressions is essential for writing clear and efficient code in Rust and many other programming languages.

1

Create the number variable

Create a variable called number and set it to 10.

Rust

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

Need a hint?

Use let number = 10; inside the main function.

2

Create the result variable with if-else expression

Create a variable called result that uses an if-else expression to check if number is greater than 0. If yes, set result to "Positive", else set it to "Not positive".

Rust

fn main() {
    let number = 10;
    // Create result using if-else expression
    // Your code here
}

Need a hint?

Use let result = if number > 0 { "Positive" } else { "Not positive" };.

3

Print the result

Add a println! statement to print the value of result.

Rust

fn main() {
    let number = 10;
    let result = if number > 0 { "Positive" } else { "Not positive" };
    // Print the result
    // Your code here
}

Need a hint?

Use println!("{}", result); to print the result.

4

Run and see the output

Run the program and observe the output. It should print Positive.

Rust

fn main() {
    let number = 10;
    let result = if number > 0 { "Positive" } else { "Not positive" };
    println!("{}", result);
}

// Run the program to see the output

Need a hint?

The program should print Positive because 10 is greater than 0.