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!