Loops in Rust: for, while, and loop

Rust

J"Rust is like C++ went to therapy, learned about memory safety, and came back as the responsible adult in the programming world—minus the midlife crisis!"

 

Why Repeat Yourself When Rust Can Do It for You? 

Programming without loops is like making coffee one drop at a time.  Painful, right? Rust offers three looping mechanisms—for, while, and loop—to make repetition easy, efficient, and even fun! 

1. for Loop: The Smart Way to Iterate 

for is the go-to loop for iterating over ranges, collections, and anything iterable.

a) Basic for Loop

fn main() {
    for number in 1..=5 {
        println!("Counting: {}", number);
    }
}

 1..=5 means from 1 to 5 (inclusive).  1..5 would mean from 1 to 4 (exclusive).

b) Looping Through an Array

fn main() {
    let fruits = ["Apple", "Banana", "Cherry"];
    for fruit in fruits.iter() {
        println!("I love {}!", fruit);
    }
}

 .iter() is used to iterate safely over an array.

2. while Loop: Keep Going Until It’s False 

Use while when looping until a condition is no longer true.

a) Basic while Loop

fn main() {
    let mut countdown = 5;
    while countdown > 0 {
        println!("T-minus {}...", countdown);
        countdown -= 1;
    }
    println!("Liftoff!");
}

Great for loops where the end condition isn’t predefined.

3. loop: The Infinite Power Loop

loop runs forever unless explicitly stopped with break.

a) Basic loop

fn main() {
    let mut count = 0;
    loop {
        println!("Looping forever... or not?");
        count += 1;
        if count == 3 {
            println!("Breaking out!");
            break;
        }
    }
}

Best for when you don’t know when to stop but control it inside the loop.

Wrapping Up 

Now you’ve mastered:  for loops for iterating over things.  while loops for condition-based repetition.  loop for infinite madness (unless you break).