fn main() {
println!("Hello, world!");
}fn means function. main function is the beginning of every Rust program.
println! prints text to the console and its ! indicate that it’s a macro instead of a function.
💡 Rust files should have .rs file extension and if you’re using more than one word for the file name, follow the snake_case.
compiling via rustc file.rs
executing by ./file on Linux and Mac or file.exe on Windows
💯 These are the other usages of println! macro,
fn main() {
println!("{}, {}!", "Hello", "world"); // Hello, world!
println!("{0}, {1}!", "Hello", "world"); // Hello, world!
println!("{greeting}, {name}!", greeting="Hello", name="world"); // Hello, world!
println!("{:?}", [1,2,3]); // [1, 2, 3]
println!("{:#?}", [1,2,3]);
/*
[
1,
2,
3
]
*/
// 🔎 format! macro is used to store the formatted STRING
let x = format!("{}, {}!", "Hello", "world");
println!("{}", x); // Hello, world!
}