Common Concepts in Rust 2

Functions in Rust

fn main() {
    add(2, 3);
}

fn add(x: i32, y: i32) {
    println!("The sum of x and y is {}", x + y);
}

• it does not matter where you define your functions in the file, above main / below main.
• each parameter must have type.

Expressions vs Statements

• Statements are instructions that perform some action and do not return a value.
• Expressions evaluate to a resultant value

fn main() {
    // statement
    let x = 5;

    // expression
    let y = {
        let z = 3;
        z + 1
    };

    println!("x is {}", x);
    println!("y is {}", y);
}

Note that z+1 does not have a ;

Returning value in Function

fn main() {
    let x = plus_one(5);

    println!("The value of x is: {x}");
}

fn plus_one(x: i32) -> i32 {
    x + 1
}

Note that we defined the type of return by ->