Tuples are fixed length things that can contain elements of different types. Here’s one:
fn main() {
let tup: (i32, f64, u8) = (500, 6.4, 1); // specifying the types is optional
let (x, y, z) = tup; // this is called destructuring
println!("The value of y is: {y}");
// 6.4
// access an element directly using . then the index (0-indexed)
let five_hundred = tup.0;
}The tuple without any values is called “unit”. This value and its corresponding type are both written () and represent an empty value or an empty return type. Expressions implicitly return the unit value if they don’t return any other value.
Arrays are also fixed-length, and must contain things of the same type. You define them like this
let a: [i32; 5] = [1, 2, 3, 4, 5];
// ^^^^^^ an array of i32 things, 5 things long
let a = [3; 5]; // a shorter way of declaring [3, 3, 3, 3, 3]You can access things in arrays by index like this
fn main() {
let a = [1, 2, 3, 4, 5];
let first = a[0];
let second = a[1];
}You can get a runtime error if you use a list index out of range, when the index is some value determined at runtime. This protects you from accessing memory that doesn’t belong to your program