Destructuring Rust Structs with Pattern Matching

Introduction

In this lab, you will learn about destructuring structs in Rust, which allows you to extract individual fields and their values from a struct using pattern matching.

Note: If the lab does not specify a file name, you can use any file name you want. For example, you can use main.rs, compile and run it with rustc main.rs && ./main.

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL rust(("`Rust`")) -.-> rust/BasicConceptsGroup(["`Basic Concepts`"]) rust(("`Rust`")) -.-> rust/DataTypesGroup(["`Data Types`"]) rust(("`Rust`")) -.-> rust/FunctionsandClosuresGroup(["`Functions and Closures`"]) rust(("`Rust`")) -.-> rust/MemorySafetyandManagementGroup(["`Memory Safety and Management`"]) rust/BasicConceptsGroup -.-> rust/variable_declarations("`Variable Declarations`") rust/DataTypesGroup -.-> rust/integer_types("`Integer Types`") rust/DataTypesGroup -.-> rust/string_type("`String Type`") rust/FunctionsandClosuresGroup -.-> rust/function_syntax("`Function Syntax`") rust/FunctionsandClosuresGroup -.-> rust/expressions_statements("`Expressions and Statements`") rust/MemorySafetyandManagementGroup -.-> rust/lifetime_specifiers("`Lifetime Specifiers`") subgraph Lab Skills rust/variable_declarations -.-> lab-99314{{"`Destructuring Rust Structs with Pattern Matching`"}} rust/integer_types -.-> lab-99314{{"`Destructuring Rust Structs with Pattern Matching`"}} rust/string_type -.-> lab-99314{{"`Destructuring Rust Structs with Pattern Matching`"}} rust/function_syntax -.-> lab-99314{{"`Destructuring Rust Structs with Pattern Matching`"}} rust/expressions_statements -.-> lab-99314{{"`Destructuring Rust Structs with Pattern Matching`"}} rust/lifetime_specifiers -.-> lab-99314{{"`Destructuring Rust Structs with Pattern Matching`"}} end

structs

Similarly, a struct can be destructured as shown:

fn main() {
    struct Foo {
        x: (u32, u32),
        y: u32,
    }

    // Try changing the values in the struct to see what happens
    let foo = Foo { x: (1, 2), y: 3 };

    match foo {
        Foo { x: (1, b), y } => println!("First of x is 1, b = {},  y = {} ", b, y),

        // you can destructure structs and rename the variables,
        // the order is not important
        Foo { y: 2, x: i } => println!("y is 2, i = {:?}", i),

        // and you can also ignore some variables:
        Foo { y, .. } => println!("y = {}, we don't care about x", y),
        // this will give an error: pattern does not mention field `x`
        //Foo { y } => println!("y = {}", y),
    }

    let faa = Foo { x: (1, 2), y: 3 };

    // You do not need a match block to destructure structs:
    let Foo { x : x0, y: y0 } = faa;
    println!("Outside: x0 = {x0:?}, y0 = {y0}");
}

Summary

Congratulations! You have completed the Structs lab. You can practice more labs in LabEx to improve your skills.

Destructuring Rust Structs with Pattern Matching

Introduction

Skills Graph

structs

Summary

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