Mutable Variables with let mut

Snippet

Mutable Variables with let mut

In Rust, variables are immutable by default for safety. Using 'let mut' makes a variable mutable, allowing you to change its value after assignment. This is different from references - 'mut' applies to the variable itself, not how you access it.

snippet.rs
rust
fn main() {
    let mut counter = 0;
    counter += 1;
    println!("Counter value: {}", counter);
    
    let name = String::from("Alice");
    let mut nickname = name;
    nickname.push_str("~");
    println!("Nickname: {}", nickname);
}

Breakdown

let mut counter = 0;

Declares a mutable integer variable 'counter' with initial value 0

counter += 1;

Modifies the variable's value since it is mutable

let mut nickname = name;

'mut' allows reassignment of the binding itself

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Mutable Variables with let mut

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