The unit type () in Rust represents the absence of a value and is used for functions that do not return data.
The unit type () in Rust is a type with exactly one value, also written as (), representing the absence of a meaningful return value. It is used when a function performs an action but does not need to return data, similar to void in other languages.
fn say_hello() {
println!("Hello!");
}
fn main() {
let result: () = say_hello(); // Returns ()
}
The unit type () is Rust's way of saying a function does nothing useful to return. Think of it like a receipt that says "Transaction Complete" but contains no actual data. You use it whenever a function just runs code, like printing to the screen, without needing to give you a result back.