How to Check If &Str Contains Enum In Rust?

3 minutes read

To check if a &str contains an enum in Rust, you can use pattern matching to match the enum variant with the string. You can create a function that takes a &str and checks if it matches the enum variant using a match statement. If the enum is found in the string, return true, otherwise return false. Here is an example code snippet:

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
enum MyEnum {
    Variant1,
    Variant2,
}

fn contains_enum(input: &str) -> bool {
    match input {
        "Variant1" => true,
        "Variant2" => true,
        _ => false,
    }
}

fn main() {
    let text = "Some text with MyEnum::Variant1";
    
    if contains_enum(text) {
        println!("Contains the enum variant");
    } else {
        println!("Does not contain the enum variant");
    }
}


In this example, the function contains_enum checks if the input string contains any of the enum variants Variant1 or Variant2. You can expand the match statement to include all enum variants and update the logic as needed for your specific use case.


What is &str in rust?

&str in Rust is a reference to a string slice, which is a contiguous sequence of UTF-8 encoded characters in memory. It is a borrowed type, meaning it does not own the data it references, but instead points to the memory location where the string is stored. This allows for efficient copying and manipulation of strings without unnecessary memory allocations.&str is commonly used to represent string literals, string slices, and borrowed strings in Rust programs.


What is the syntax for defining an enum in rust?

The syntax for defining an enum in Rust is as follows:

1
2
3
4
5
6
7
8
9
enum MyEnum {
    Variant1,
    Variant2,
    Variant3(i32),         // Enum variant with associated data
    Variant4 {             // Enum variant as a struct
        field1: i32,
        field2: String,
    },
}



How to use pattern matching with enums in rust?

Pattern matching with enums in Rust allows you to easily handle different cases or variants of an enum by using match expressions. Here's how you can use pattern matching with enums in Rust:

  1. Define an enum with multiple variants:
1
2
3
4
5
enum Shape {
    Circle(u32),
    Rectangle(u32, u32),
    Triangle(u32, u32, u32),
}


  1. Use match expressions to handle each variant:
 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
fn calculate_area(shape: Shape) -> u32 {
    match shape {
        Shape::Circle(radius) => 3 * radius * radius,
        Shape::Rectangle(width, height) => width * height,
        Shape::Triangle(side1, side2, side3) => {
            let s = (side1 + side2 + side3) / 2;
            (s * (s - side1) * (s - side2) * (s - side3)).sqrt() as u32
        }
    }
}

fn main() {
    let circle = Shape::Circle(5);
    let rectangle = Shape::Rectangle(3, 4);
    let triangle = Shape::Triangle(3, 4, 5);

    println!("Area of circle: {}", calculate_area(circle));
    println!("Area of rectangle: {}", calculate_area(rectangle));
    println!("Area of triangle: {}", calculate_area(triangle));
}


In this example, the calculate_area function uses a match expression to handle each variant of the Shape enum and calculate the area accordingly.

  1. Run the code and see the output:
1
2
3
Area of circle: 75
Area of rectangle: 12
Area of triangle: 6


By using pattern matching with enums in Rust, you can easily handle different cases or variants of an enum and perform specific actions based on each case.

Facebook Twitter LinkedIn Telegram

Related Posts:

To use "enum" values in select options in Laravel, you first need to define the enum values in your model as a static function. Then, in your view file, you can use the enum values in a select dropdown by looping through the enum values and displaying ...
In GraphQL schema, you can define a nested enum type by creating separate enum types within the main schema definition. These nested enum types can then be referenced within other types in the schema, allowing you to define a more complex and structured data m...
To call a Python asynchronous function from Rust, you can use the pyo3 crate, which allows Rust to interface with Python. First, ensure that you have both Rust and Python installed on your system. Next, add the pyo3 crate to your Cargo.toml file.Then, you can ...
To iterate prefixes and suffixes of a string in Rust, you can use the windows() method on the string slice to create an iterator over substrings of a specified length. For prefixes, you can start with a length of 1 and increment it until you reach the length o...
To completely remove rust installed by Ubuntu, you can use the following commands in the Terminal:First, uninstall Rust using apt-get remove command:sudo apt-get remove rustcNext, remove any leftover files and configurations:sudo apt-get purge rustcFinally, cl...