Rust Structs
Structs
A struct (short for "structure") is a custom data structure that lets you group related values together.
You can think of a struct like a mini-database for one thing, like a person with a name and age.
Create a Struct
You define a struct using the struct keyword and place the fields (variables) inside:
Example
struct Person {
name: String,
age: u32,
can_vote: bool,
}
name: String,
age: u32,
can_vote: bool,
}
Once you have a struct, you can create an object of it.
Then, you can access the fields of the struct using dot syntax (.):
Example
// Create a Struct called Person
struct Person {
name: String,
age: u32,
can_vote: bool,
}
// Create a Person object
let user = Person {
name: String::from("John"),
age: 35,
can_vote: true,
};
// Access and print the values
println!("Name: {}", user.name);
println!("Age: {}", user.age);
println!("Can vote? {}", user.can_vote);
Try it Yourself »
struct Person {
name: String,
age: u32,
can_vote: bool,
}
// Create a Person object
let user = Person {
name: String::from("John"),
age: 35,
can_vote: true,
};
// Access and print the values
println!("Name: {}", user.name);
println!("Age: {}", user.age);
println!("Can vote? {}", user.can_vote);
Fields are similar to variables, but they belong to a struct. Since they are part of a larger structure (like Person or Car), they are called fields in Rust, not regular variables.
Change a Field
To change a value inside a struct, you must make the struct object mutable by using mut:
Example
struct Person {
name: String,
age: u32,
}
let mut user = Person {
name: String::from("John"),
age: 35,
};
user.age = 36; // Change value of age
println!("Name: {}", user.name);
println!("Updated age: {}", user.age);
Try it Yourself »
name: String,
age: u32,
}
let mut user = Person {
name: String::from("John"),
age: 35,
};
user.age = 36; // Change value of age
println!("Name: {}", user.name);
println!("Updated age: {}", user.age);
Why Use Structs?
- To group related data in a clean way
- To make your code easier to read and maintain
- To create real-world examples, like users, books, cars, etc.