LANGUAGE » RUST

Array

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Reference:doc.rust-lang.org

Basic ​

Slice is subset of an array. They work in the same way.

rust
let myarray = [1, 5, 9, 13, 17];
let myarray: [i32; 5] = [1, 5, 9, 13, 17];  // Type signature is superfluous

let myslice = &myarray[1 .. 3];  // Same as myarray[1:3] in python [inclusive:exclusive]
let myslice: &[i32] = &myarray[1 .. 3];  // Type signature is superfluous

let emptyarray = [];
let emptyslice = &[];

let mut vec = Vec::new();
vec.push(1);
vec.push(2);

Two-dimensional array:

rust
const VALUE: u8 = 0;
const X_SIZE: usize = 3;
const Y_SIZE: usize = 4;
let mut matrix = [[VALUE; X_SIZE]; Y_SIZE];
matrix[y][x] = 1;

Three-dimensional array:

rust
const VALUE: u8 = 0;
const X_SIZE: usize = 3;
const Y_SIZE: usize = 4;
const Z_SIZE: usize = 5;
let mut space = [[[VALUE; X_SIZE]; Y_SIZE]; Z_SIZE];
space[z][y][x] = 1;

Destructure into simpler types:

rust
let [head @ .., penultimate, last] = myarray;
let [first, middle @ .., last] = myarray;
let [first, second, tail @ ..] = myarray;

Iterate an array:

rust
for value in &myarray {
    println!("{value}");
}

Methods ​

MethodDescription
getSafer way to access index of array/slice.
is_emptyReturns true if the vector contains no elements.
iterReturns an iterator over the slice.
joinFlattens a slice into a single value, placing a given separator between each.
lenGet the length of the array/slice.
pushAppends an element to the back of a collection.

Examples ​

Accessing elements:

rust
let first = myarray[0];
let first = myarray.get(0);  // More safe

Borrow a slice to a function:

rust
fn analyze_slice(slice: &[i32]) {
    println!("First element of the slice: {}", slice[0]);
    println!("The slice has {} elements", slice.len());
}

fn main() {
    let myarray = [1, 5, 9, 13, 17];
    println!("Array analyze:");
    analyze_slice(&myarray);
    println!("Slice analyze:");
    analyze_slice(&myarray[1 .. 3]);
}

Loop an array/slice:

rust
for i in 0 .. slice.len() + 1 {
    match slice.get(i) {
        Some(val) => println!("{}: {}", i, val),
        None => println!("{}: Out of bound", i),
    }
}