Cheatsheet

NOTE: These are draft notes.

TODO: Figure out where to put this in the book.

Here's the high level:

Create An Immutable Variable

let alfa = String::from("apple");

Create A Mutable Variable

let mut alfa = String::from("apple");

Create A Struct

struct Widget {
  alfa: String,
  bravo: String
}

Create A Function With No Arguments Or Return Value

fn widget() {
  println!("this is widget");
}

Create A Function That Has One Argument Reference But No Return Value

fn widget(thing: &String) {
  println!("widget to {}", thing);
}

Create A Function With Two Arguments But No Return Value

fn widget(thing1: &String, thing2: &String) {
  println!(
    "widget got {} and {}",
    thing1,
    thing2
  );
}

Create A Function With A Return Value But No Arguments

fn widget() -> String {
  let alfa = String::from("apple");
  alfa
}

Create A Function With A Return Value And An Argument Reference

fn widget(thing: &String) -> String {
  println!("widget got {}", thing);
  let alfa = String::from("apple");
  alfa
}

Create A Function That Takes A Mutable Reference Argument

fn widget(thing: &mut String) {
  thing.push_str("additional characters")
}