What is a Struct?

Part of the Logic & Flow section of Coddy's Rust journey — lesson 20 of 66.

So far, you've worked with individual pieces of data - single numbers, strings, and collections like vectors. But what happens when you need to group related information together? For example, how would you represent a person with a name, age, and email address?

This is where structs come in. A struct is Rust's way of creating custom data types by bundling related values into a single, organized unit.

Each piece of data inside a struct is called a field. Fields have names and types, making it clear what each piece of information represents.

Example of a struct with different field types:

struct Person {
    name: String,
    age: u32,
    active: bool,
}

Here a Person struct have a name field of type String, an age field of type u32, and an active field of type bool.

Cheat sheet

A struct is a custom data type that groups related values together. Each value inside a struct is called a field, which has a name and a type.

Defining a struct:

struct Person {
    name: String,
    age: u32,
    active: bool,
}

In this example, Person is a struct with three fields: name (String), age (u32), and active (bool).

Try it yourself

This lesson doesn't include a code challenge.

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in Logic & Flow

1Advanced Control Flow

The 'match' Expression Matching Multiple Values Matching Ranges The 'if let' Expression Loops as Expressions Recap - Simple Command Parser

4Grouping Data with Structs

What is a Struct?Structs Overview Accessing Struct Fields Mutable Structs Structs as Function Parameters Tuple Structs Recap - Create a Book Struct

7Handling Errors with 'Result'

What is a 'Result'?Using 'match' with 'Result'is_ok() and is_err()Shortcuts: unwrap and expect The Question Mark Operator '?'Parsing Strings to Numbers Recap - Safe Division Function

10Closures & Anonymous Functions

What is a Closure?Defining a Simple Closure Closures with Parameters Capturing the Environment Recap - Simple Adder Closure

2Introduction to Vectors

What is a Vector?Creating a Vector Adding Elements with push Accessing Vector Elements Iterating Over a Vector Mutable Iteration Removing Elements Recap - Basic Score Tracker

5Key-Value Pairs with Hash Maps

What is a Hash Map?Creating a Hash Map Inserting Key-Value Pairs Accessing Values Iterating Over a Hash Map Updating a Value Removing a Pair Recap - Word Counter

8Project: Simple Item Inventory

Project Setup Adding an Item Checking Stock Selling an Item Putting it all together

11Final Challenges

Recap - Unique Items Recap - User Profile Validator Recap - Grade Summarizer

3Command-Line To-Do List

Project Setup Adding a Task Viewing All Tasks Removing a Task Final Code

6Handling Absence with 'Option'

What is an 'Option'?Using 'match' with 'Option'is_some() and is_none()Unwrapping an 'Option'The expect Providing a Default: unwrap_or Recap - Find an Element

9String Slices and More

String vs. &str Creating String Slices Slices as Function Parameters Other Slices Recap - Find First Word