rust / beginner
Snippet
Defining and Calling Functions in Rust
Functions are reusable blocks of code in Rust. They are defined using the `fn` keyword followed by the function name, parameters in parentheses, and an optional return type. Parameters need type annotations. The return type is specified after `->`. If a function returns a value, the last expression is implicitly returned. You can call functions by using their name followed by parentheses, passing arguments that match the parameter types.
snippet.rs
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fn greet(name: &str) -> String {format!("Hello, {}!", name)}fn main() {let message = greet("World");println!("{}", message);let result = add(15, 27);println!("15 + 27 = {}", result);}fn add(a: i32, b: i32) -> i32 {a + b}
Breakdown
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fn greet(name: &str) -> String {
Function definition with a string slice parameter and String return type
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format!("Hello, {}!", name)
Macro that creates a formatted String with interpolation
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}
Function body closing brace - implicit return of formatted string
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fn main() {
Entry point function - Rust programs start here
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let message = greet("World");
Calling greet with a string literal, storing result in message
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println!("{}", message);
Macro to print the message to console
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let result = add(15, 27);
Calling add function with two i32 values
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fn add(a: i32, b: i32) -> i32 {
Function with two i32 parameters returning i32, no explicit return needed