Table of Contents📚

• The match keyword
• Multiple patterns
• Checking if a value is in a range

Pattern matching 🔍

The match keyword

The match keyword is similar the the switch keyword in other languages.

It is a conditional operator, it is used to do different things based on the value of a variable.

for example:

let number = 2;

match number {
    1 => println!("the number is 1"),
    2 => println!("the number is two"),
    3 => {
        println!("the number is 3");
        println!("the number is 3 again");
      },
    _ => println!("the number is not one, two or three")
}

the _ is the wildcard, it will be used if no other match is found.

You must add {} if you want to execute multiple lines of code on a match.

The checked value and all the patterns must be of the same type.

Now if we run the program :

$ cargo run
> the number is two

Multiple patterns

You can check multiple patterns at the same time with a |

let number = 3;

match number { 
    1 | 3 => println!("the number is 1 or 3"),
    _ => println!("the number is not one or three")
}

$ cargo run
> the number is 1 or 3

Checking if a value is in a range

We can also check if a number is in a range.

let number = 4;

match number { 
    1...5 => println!("the number is between 1 and 5"),
    _ => println!("the number is not between 1 and 5")
}

If we run the program :

$ cargo run
> the number is between 1 and 5

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Course created by SkwalExe and inspired by Dcode