hello-world.md

👋 Hello World

• 👋 Hello World
  • 👀 Fast Lookup
  • ⚙️ Initial Setup and Keywords
  • 💻 Hello World Example
  • 🔍 Example deep dive

👀 Fast Lookup

• Basic Rust Program: fn main() { println!("Hello, world!"); }
• Compile & Run: rustc main.rs then ./main
• Key Tools:
  • rustup: Manages Rust versions and associated tools
  • rustc: The Rust compiler that compiles source code into executable binary
• Key Syntax: println! is a macro (note the !), functions use fn, statements end with ;

⚙️ Initial Setup and Keywords

Install Rust using rustup, which is the recommended way to install Rust. It manages Rust versions and associated tools.

• rustup commands:
  • rustup update: Updates Rust to the latest version.
  • rustup doc: Opens the Rust documentation in the browser.

💻 Hello World Example

main.rs:

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

To run the program, use the following commands in your terminal:

rustc main.rs  # Compiles the Rust code
./main        # Runs the compiled Rust program

This will output:

Hello, world!

🔍 Example deep dive

• The main function is the entry point of a Rust program.
• Rust uses 4 spaces for indentation.
• println! is a macro that prints text to the console. The ! indicates that it is a macro, not a function.
  • In this stage, let's just understand that macros and functions are a bit different.
• ; is used to denote the end of a statement in Rust.
• rustc is the Rust compiler that compiles the source code into an executable binary.
  • We will use cargo for managing projects and dependencies later, which simplifies this process instead of using rustc directly.