Rust Data Structures
Data Structures
In Rust, data structures are used to store and organize values.
Rust provides many built-in data structures. Each is used to handle data in different ways.
Some of the most common are:
- Array
- Vector (Vec)
- Tuple
- HashMap
We will explore all of them in detail later, but for now, here's a quick introduction to each one.
Arrays
An array in Rust is a fixed-size list of values, all of the same type.
You cannot grow or shrink an array after it's created.
To access an array element, refer to its index number.
Array indexes start with 0: [0] is the first element, [1] is the second element, etc.
Example
let fruits = ["apple", "banana", "orange"];
println!("Last fruit: {}", fruits[2]);
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Vectors
A vector is a resizable array. Unlike regular arrays, vectors can grow or shrink in size.
Example
let mut fruits = vec!["apple", "banana"];
fruits.push("cherry");
println!("Last fruit: {}", fruits[2]);
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Tuples
A tuple can hold multiple values of different types. It is useful when grouping different types together.
You access tuple elements using a dot and an index number, like person.1, etc:
Example
let person = ("John", 30, true);
println!("Name: {}", person.0);
println!("Age: {}", person.1);
println!("Is active: {}", person.2);
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HashMaps
A HashMap stores key-value pairs. It lets you look up a value using a key.
To use HashMap, you must import it from the standard library.
Example
// Import HashMap
use std::collections::HashMap;
fn main() {
let mut capitalCities = HashMap::new();
capitalCities.insert("France", "Paris");
capitalCities.insert("Japan", "Tokyo");
println!("Capital of Japan is {}", capitalCities["Japan"]);
}
Try it Yourself »
Data Structures Overview
| Data Structure | Use Case | Can Grow? |
|---|---|---|
| Array | Fixed-size list of same-type values | No |
| Vector (Vec) | Growable list of same-type values | Yes |
| Tuple | Group different types together | No |
| HashMap | Key-value lookup | Yes |
Next, let's take a closer look at each data structure in more detail.
