Getting Started

fn test(){
  println!("This is a function!");
}
fn main(){
  test();
}

See: Functions

// Line Comments
/\*.............Block Comments \*/
/// Outer doc comments
//! Inner doc comments

See: Comment

// Initializing and declaring a variable
let some\_variable = "This\_is\_a\_variable";
// Making a variable mutable
let mut mutable\_variable = "Mutable";
// Assigning multiple variables
let (name, age) = ("ElementalX", 20);
// (Global) constant
const SCREAMING_SNAKE_CASE:i64 = 9;

// Prints the output
print!("Hello World\n");
// Appends a new line after printing
println!("Appending a new line");
// Prints as an error
eprint!("This is an error\n");
// Prints as an error with new line
eprintln!("This is an error with new line");

// Single Placeholder
println!("{}", 1);
// Multiple Placeholder
println!("{} {}", 1, 3);
// Positional Arguments
println!("{0} is {1} {2}, also {0} is a {3} programming language", "Rust", "cool", "language", "safe");
// Named Arguments
println!("{country} is a diverse nation with unity.", country = "India");
// Placeholder traits :b for binary, :0x is for hex and :o is octal
println!("Let us print 76 is binary which is {:b} , and hex equivalent is {:0x} and octal equivalent is {:o}", 76, 76, 76);
// Debug Trait
println!("Print whatever we want to here using debug trait {:?}", (76, 'A', 90));
// New Format Strings in 1.58
let x = "world";
println!("Hello {x}!");

fn main() {
  println!("Hello, World!");
}

#Compiling and Running

$ rustc Hello\_World.rs
$ ./Hello\_World
Hello, World!