tutorial-03-syntax_basics.rs

/**
 * 3 Syntax basics
 * http://doc.rust-lang.org/tutorial.html#syntax-basics
 *
 * @license MIT license <http://www.opensource.org/licenses/mit-license.php>
 */
fn main() {
	/*
	 * The let keyword introduces a local variable.
	 * Variables are immutable by default.
	 * To introduce a local variable that you can re-assign later, use let mut instead.
	 */
	let hi = "hi";
	let mut count = 0;

	while count < 10 {
		println!("{}, count: {}", hi, count);
		count += 1;
	}

	/*
	 * Although Rust can almost always infer the types of local variables,
	 * you can specify a variable's type by following it in the let with a colon, then the type name.
	 * Static items, on the other hand, always require a type annotation.
	 */
	static MONSTER_FACTOR: f64 = 57.8;
	let monster_size = MONSTER_FACTOR * 10.0;
	println!("{}", monster_size);
	let monster_size = 50;
	println!("{}", monster_size);

	/*
	 * 3.4 Syntax extensions
	 * http://doc.rust-lang.org/tutorial.html#syntax-extensions
	 */
	// {} will print the "default format" of a type
	println!("{} is {}", "the answer", 43);

	// // {:?} will conveniently print any type
	println!("what is this thing: {:?}", monster_size);
}