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Rust · BeginnerSnippet

Control Flow with If Expressions

In Rust, 'if' is an expression, not just a statement. This means it returns a value that can be assigned to a variable, provided all branches return the same type.

snippet.rs

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fn main() {
    let number = 7;
    let condition = if number < 10 {
        true
    } else {
        false
    };
    println!("Condition is {condition}");
}

controlflowsyntax

Rust · BeginnerSnippet

Working with Fixed-Size Arrays

Arrays in Rust have a fixed length and must contain elements of the same type. They are useful when you want your data allocated on the stack rather than the heap.

snippet.rs

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fn main() {
    let a: [i32; 3] = [10, 20, 30];
    let first = a[0];
    let length = a.len();
    println!("First: {first}, Length: {length}");
}

arraysdatatypes

Rust · BeginnerSnippet

Variables and Immutability

In Rust, variables are immutable by default, meaning their value cannot change once bound. To allow a variable to be updated, you must explicitly use the 'mut' keyword.

snippet.rs

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fn main() {
    let x = 5;
    // x = 6; // This would cause a compile error
    let mut y = 10;
    y = 11; // This is allowed
    println!("x: {x}, y: {y}");
}

syntaxdatatypes

Rust · BeginnerSnippet

Basic Error Handling with Option

Rust uses the Option enum to represent a value that might be missing, instead of using null. 'match' is used to safely handle both the presence (Some) and absence (None) of the value.

snippet.rs

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fn main() {
    let some_value = Some(5);
    let no_value: Option<i32> = None;
 
    match some_value {
        Some(val) => println!("Value: {val}"),
        None => println!("No value found"),
    }
}

errorhandlingdatatypes

Rust · BeginnerSnippet

Defining Basic Functions

Functions are declared using 'fn'. Parameters must have explicit type annotations, and the return type is specified after an arrow '->'. The last expression in a function is its return value.

snippet.rs

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fn add(a: i32, b: i32) -> i32 {
    a + b
}
 
fn main() {
    let sum = add(5, 10);
    println!("The sum is: {sum}");
}

functionssyntax

Rust · BeginnerSnippet

Defining Basic Enums

Enums (enumerations) allow you to define a type by enumerating its possible variants. Variants can also hold data.

snippet.rs

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enum WebEvent {
    PageLoad,
    PageUnload,
    KeyPress(char),
}
 
let load = WebEvent::PageLoad;
let press = WebEvent::KeyPress('x');

syntaxdatatypes

Rust · BeginnerSnippet

Using Vectors for Dynamic Lists

Vectors allow you to store a variable number of values next to each other in memory. Unlike arrays, they can grow or shrink.

snippet.rs

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let mut v: Vec<i32> = Vec::new();
v.push(5);
v.push(6);
 
let second = v[1];
println!("The second element is {}", second);

datatypessyntax

Rust · BeginnerSnippet

Defining and Instantiating Structs

Structs allow you to create custom data types by grouping related values together. Each field has a name and a type.

snippet.rs

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struct User {
    username: String,
    email: String,
    active: bool,
}
 
fn main() {
    let user1 = User {
        email: String::from("[email protected]"),
        username: String::from("someuser123"),
        active: true,
    };
}

syntaxdatatypes