Variables - Rust Programming

Rust names are immutable by default. mut allows reassignment, and a second let shadows a name with a new binding.

Program

Play the program to watch count change by reassignment and then by shadowing.

variables.rs

fn main() {
    let mut count = 1;
    count = count + 2;
    let count = count * 10;
    println!("{count}");
}

mut `let mut` allows a binding to be reassigned.

reassignment `count = count + 2` updates the existing mutable value.

shadowing A new `let count` creates a fresh binding that hides the old one.