Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

fn main() {
    // --- Stack-allocated Copy type ---
    let a: i32 = 5;
    let b = a;          // 'a' is COPIED; both a and b are valid
    println!("a={a}  b={b}");

// --- Heap-allocated String: MOVE semantics ---
    let s1 = String::from("hello");
    let s2 = s1;        // s1 is MOVED into s2; s1 is no longer valid
    // println!("{s1}"); // <-- compile error: value borrowed after move
    println!("s2 = {s2}");

// --- Clone to make an explicit deep copy ---
    let s3 = String::from("world");
    let s4 = s3.clone();
    println!("s3={s3}  s4={s4}");  // both valid after clone

// --- Ownership and functions ---
    let greeting = String::from("hi");
    takes_ownership(greeting);
    // println!("{greeting}"); // compile error: moved into function

let num = 42i32;
    makes_copy(num);
    println!("num still valid: {num}"); // ok — i32 is Copy

// --- Returning ownership ---
    let returned = gives_ownership();
    println!("returned = {returned}");
} // 's2', 's4', 'returned' are dropped here

fn takes_ownership(s: String) {
    println!("took ownership of: {s}");
} // s is dropped here

fn makes_copy(n: i32) {
    println!("copy of: {n}");
}

fn gives_ownership() -> String {
    String::from("transferred")
}