Exploring Rust Pattern Matching

Introduction

In this lab, we will explore how Rust provides pattern matching using the match keyword, which functions similarly to a switch statement in C.

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(("`Rust`")) -.-> rust/AdvancedTopicsGroup(["`Advanced Topics`"]) rust/BasicConceptsGroup -.-> rust/variable_declarations("`Variable Declarations`") rust/DataTypesGroup -.-> rust/boolean_type("`Boolean Type`") 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`") rust/AdvancedTopicsGroup -.-> rust/operator_overloading("`Traits for Operator Overloading`") subgraph Lab Skills rust/variable_declarations -.-> lab-99309{{"`Rust Pattern Matching Exploration`"}} rust/boolean_type -.-> lab-99309{{"`Rust Pattern Matching Exploration`"}} rust/string_type -.-> lab-99309{{"`Rust Pattern Matching Exploration`"}} rust/function_syntax -.-> lab-99309{{"`Rust Pattern Matching Exploration`"}} rust/expressions_statements -.-> lab-99309{{"`Rust Pattern Matching Exploration`"}} rust/lifetime_specifiers -.-> lab-99309{{"`Rust Pattern Matching Exploration`"}} rust/operator_overloading -.-> lab-99309{{"`Rust Pattern Matching Exploration`"}} end

match

Rust provides pattern matching via the match keyword, which can be used like a C switch. The first matching arm is evaluated and all possible values must be covered.

fn main() {
    let number = 13;
    // TODO ^ Try different values for `number`

    println!("Tell me about {}", number);
    match number {
        // Match a single value
        1 => println!("One!"),
        // Match several values
        2 | 3 | 5 | 7 | 11 => println!("This is a prime"),
        // TODO ^ Try adding 13 to the list of prime values
        // Match an inclusive range
        13..=19 => println!("A teen"),
        // Handle the rest of cases
        _ => println!("Ain't special"),
        // TODO ^ Try commenting out this catch-all arm
    }

    let boolean = true;
    // Match is an expression too
    let binary = match boolean {
        // The arms of a match must cover all the possible values
        false => 0,
        true => 1,
        // TODO ^ Try commenting out one of these arms
    };

    println!("{} -> {}", boolean, binary);
}

Summary

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

Rust Pattern Matching Exploration

Introduction

Skills Graph

match

Summary

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