Match Expression

What Is a match Expression?

Match expression checks if the current value corresponds to any value within the list of values. Match expression are similar to switch statement in languages like C and C++. They give a more compact code when compared with the if/else construct.

  • Syntax Match expression uses a match keyword. The match expression can be written in two different ways, which are given below:

  • Method 1: If you do not want to assign a value to the result variable from within the match block

  fn main() {
    // define a variable 
    let x = 5;
    // define match expression
    match x {
        1 => println!("Java"),
        2 => println!("Python"),
        3 => println!("C++"),
        4 => println!("C#"),
        5 => println!("Rust"),
        6 => println!("Kotlin"),
        _ => println!("Some other value"),
    };
}

output:-

  Rust

Method 2:

If you want to assign a value to the result variable from within the match block

  fn main(){
   // define a variable
   let course = "Rust";
   // return value of match expression in a variable
   let found_course = match course {
      "Rust" => "Rust",
      "Java" => "Java",
      "C++" => "C Plus Plus",
      "C#" => "C Sharp",
      _ => "Unknown Language"
   };
   println!("Course name : {}",found_course);
}

output:-

  Course name : Rust

Quiz

Test your understanding of match expression in Rust.

--- primaryColor: steelblue secondaryColor: '#e8e8e8' textColor: black shuffleQuestions: false shuffleAnswers: true locale: en --- # What is the output of the following code? ``` fn main() { let x = 21; match x { 1 => println!("Java"), 2 => println!("Python"), 3 => println!("C++"), 4 => println!("C#"), 5 => println!("Rust"), 6 => println!("Kotlin"), _ => println!("Some other value"), } } ``` - [ ] Python
Java
- [ ] Some other value
# What is the output of the following code? ``` fn main() { let mut x = 2; match x { 1 => println!("Java"), 2 => println!("Python"), 3 => println!("C++"), 4 => println!("C#"), 5 => println!("Rust"), 6 => println!("Kotlin"), _ => println!("Some other value"), } x = 1; match x { 1 => println!("Java"), 2 => println!("Python"), 3 => println!("C++"), 4 => println!("C#"), 5 => println!("Rust"), 6 => println!("Kotlin"), _ => println!("Some other value"), } } ``` - [ ] Python
Java
- [ ] Some other value
- [ ] Java
Python
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Last updated 25 Jan 2024, 05:11 +0530 . history