rustlings/exercises/functions/functions5.rs
Roberto Vidal 2cdd61294f feat: improve watch execution mode
The `watch` command now requires user action to move to the next
exercise.

BREAKING CHANGE: this changes the behavior of `watch`.
2019-11-11 16:23:35 +01:00

49 lines
781 B
Rust

// functions5.rs
// Make me compile! Scroll down for hints :)
// I AM NOT DONE
fn main() {
let answer = square(3);
println!("The answer is {}", answer);
}
fn square(num: i32) -> i32 {
num * num;
}
// This is a really common error that can be fixed by removing one character.
// It happens because Rust distinguishes between expressions and statements: expressions return
// a value based on its operand, and statements simply return a () type which behaves just like `void` in C/C++ language.
// We want to return a value of `i32` type from the `square` function, but it is returning a `()` type...
// They are not the same. There are two solutions:
// 1. Add a `return` ahead of `num * num;`
// 2. remove `;`, make it to be `num * num`