Rust Loops

Repeating code execution in Rust

🔄 What are Loops in Rust?

Loops in Rust allow you to repeat code multiple times. Rust provides three types of loops: loop (infinite), while (conditional), and for (iterator-based) for different repetition needs. 


// Simple loop example
let mut count = 0;

loop {
    println!("Count: {}", count);
    count += 1;
    
    if count >= 3 {
        break;
    }
}

Output:

Count: 0
Count: 1
Count: 2

Types of Loops

♾️

loop

Infinite loop until break 

loop {
    // code here
    if condition {
        break;
    }
}
❓

while

Loop while condition is true 

while condition {
    // code here
}
📋

for

Loop through collections 

for item in collection {
    // code here
}
🛑

Control

break and continue keywords 

break; // exit loop
continue; // skip iteration

🔹 The loop Keyword

The loop keyword creates an infinite loop that runs until you break: 

fn main() {
    let mut counter = 0;
    
    let result = loop {
        counter += 1;
        
        if counter == 5 {
            break counter * 2; // return value from loop
        }
    };
    
    println!("Result: {}", result);
}

Output:

Result: 10

🔹 Loop Labels

Use labels to break from nested loops: 

fn main() {
    'outer: loop {
        println!("Outer loop");
        
        loop {
            println!("Inner loop");
            break 'outer; // breaks the outer loop
        }
    }
    
    println!("Done!");
}

Output:

Outer loop
Inner loop
Done!

🔹 Using continue

Skip the current iteration and continue with the next: 

fn main() {
    for number in 1..=5 {
        if number == 3 {
            continue; // skip when number is 3
        }
        println!("Number: {}", number);
    }
}

Output:

Number: 1
Number: 2
Number: 4
Number: 5

🧠 Test Your Knowledge

Which loop type runs indefinitely until you use break?