Mutable variables in Rust - Mini Project: Build & Apply

Mutable variables

📖 Scenario: Imagine you are keeping track of the number of apples in a basket. Sometimes apples are added or taken away. You want to write a program that can change the number of apples as needed.

🎯 Goal: You will create a mutable variable to hold the number of apples, change its value, and then print the final count.

📋 What You'll Learn

Create a mutable variable called apples with the initial value 5.

Change the value of apples to 10.

Print the value of apples.

💡 Why This Matters

🌍 Real World

Mutable variables let programs keep track of changing information, like counting items or updating scores.

💼 Career

Understanding mutable variables is essential for writing programs that handle data that changes over time, a common task in software development.

1

Create a mutable variable

Create a mutable variable called apples and set it to 5.

Rust

# Create a mutable variable called apples and set it to 5
# Your code here

Need a hint?

Use let mut to create a variable that can change.

2

Change the variable value

Change the value of the mutable variable apples to 10.

Rust

let mut apples = 5;
# Change apples to 10
# Your code here

Need a hint?

Assign a new value to apples without using let.

3

Print the variable

Print the value of the variable apples using println!.

Rust

let mut apples = 5;
apples = 10;
# Print the value of apples
# Your code here

Need a hint?

Use println!("{}", apples); to show the value.

4

Run and see the output

Run the program to see the final number of apples printed.

Rust

let mut apples = 5;
apples = 10;
println!("{}", apples);
# Run the program to see the output

Need a hint?

The program should print 10 because that is the final value of apples.