Understanding Ownership and Move Semantics

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Understanding Ownership and Move Semantics

Rust uses ownership to manage memory. When you assign s1 to s2, ownership of the String's heap data transfers from s1 to s2. After the move, s1 is no longer valid. Use .clone() if you need an independent copy of the data.

snippet.rs
rust
fn main() {
    let s1 = String::from("hello");
    let s2 = s1;  // s1 is moved to s2
    
    // println!("{}", s1);  // This would error!
    println!("{}", s2);  // This works fine
    
    let s3 = String::from("world");
    let s4 = s3.clone();  // Deep copy, both valid
    println!("s3: {}, s4: {}", s3, s4);
}

Breakdown

let s1 = String::from("hello");

Creates a String allocated on the heap

let s2 = s1;

Ownership moves to s2; s1 is now invalid

s1 would error

Using s1 after move triggers compile error

.clone()

Creates a deep copy; both s3 and s4 are valid

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Understanding Ownership and Move Semantics

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