Common Collections in Rust

Understand how to use Rust's common collections such as vectors, strings, and hash maps to store and manage data efficiently.

Introduction

Rust provides several collections for storing data. Unlike arrays, these collections can grow or shrink in size. This lesson will cover three fundamental collections: vectors, strings, and hash maps, exploring how to use them to manage groups of data.

Learning Objectives

• Learn how to use vectors to store lists of values in Rust.
• Understand how to manipulate strings, Rust’s collection for storing text.
• Discover how to use hash maps to associate keys with values.

Vectors

Vectors in Rust allow you to store more than one value in a single data structure that puts all the values next to each other in memory. Vectors are similar to arrays but can grow and shrink in size.

let mut v: Vec<i32> = Vec::new(); // create a new, empty vector
v.push(5); // add the value 5 to the end of the vector
v.push(6); // add the value 6 to the end of the vector

Strings

The String type in Rust is a collection of characters. It’s not just a simple array of chars due to Rust’s support for UTF-8 encoding, which means that it can store more than just ASCII.

let mut s = String::new(); // creates a new empty string
s.push_str("hello"); // appends "hello" to the string

Hash Maps

Hash maps allow you to store keys associated with values. This structure is useful when you want to look up data based on a key rather than an index like in vectors.

use std::collections::HashMap;

let mut scores = HashMap::new();
scores.insert(String::from("Blue"), 10);
scores.insert(String::from("Yellow"), 50);

Summary

In this lesson, you’ve learned about the use of common collections in Rust, including vectors, strings, and hash maps. Understanding these collections is crucial for effective data management and manipulation in Rust applications.

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