Programming a Guessing Game in Rust

cargo run

& indicates passing by reference

.read_line(&mut guess)

let mut guess = String::new();

Variables are immutable by default. Declaring a variable with mut allows it to be mutable.

io::stdin()
      .read_line(&mut guess) // & indicates passing by reference
      .expect("Failed to read line");

read_line returns a Return enum. Possible variables: Ok and Error. These are referred to as variants.

If this instance of Result is an Ok value, expect will take the return value that Ok is holding and return just that value to you so you can use it. In this case, that value is the number of bytes in the user’s input.

A function that gives a particular random number generator that is local to the current thread of execution and seeded by the operating system.

Specifies a range that is inclusive on the upper and lower bounds.

A match expression is made up of arms. An arm consists of a pattern to match against, and the code that should be run if the value given to match fits that arm’s pattern. Rust takes the value given to match and looks through each arm’s pattern in turn.

Using an _ underscore in a match arm is a catchall value.

Integers are of type i32, a 32-bit integer, unless otherwise specified.

Variables can be shadowed to convert a variable from one type to another.

https://crates.io/

This is akin to Maven central for all you Java nerds like me.

cargo doc --open