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Zeus

Hello World

Let’s write your first Zeus program! We’ll create a simple program that demonstrates the basics.

Your First Program

  1. Create a new file

    Create a file called hello.zs:

    Terminal window
    touch hello.zs

  2. Write the code

    Open hello.zs and add:

    function main(): void {
      log("Hello, World 👋");
    }

  3. Compile and run

    Terminal window
    zeus build hello.zs -o hello
    ./hello
    # Output: Hello, World 👋

Understanding the Code

Let’s break down what we wrote:

function main(): void {
  log("Hello, World 👋");
}

The main Function

Every Zeus program needs a main function—this is where execution begins:

function main(): void {
  // Your code here
}
  • function — Keyword to declare a function
  • main — The entry point function name
  • (): void — Takes no parameters, returns nothing

The log Function

log("Hello, World 👋");
  • log — Built-in function to print to stdout
  • Accepts a string (UTF-8 supported, including emojis! 🎉)

A More Interesting Example

Let’s try something with a class:

class Greeter {
  public times: i32;


  constructor(t: i32) {
    this.times = t;
  }


  public greetCount(): i32 {
    return this.times;
  }
}


function main(): i32 {
  let greeter: Greeter = new Greeter(5);
  return greeter.greetCount();
}

Save this as greeter.zs and run:

Terminal window
zeus build greeter.zs -o greeter
./greeter
echo $?
# Output: 5

Working with Arrays

Here’s an example using dynamic arrays:

function main(): i32 {
  // Create an array of integers
  let numbers: i32[] = new i32[];


  // Add some numbers
  numbers.push(10);
  numbers.push(20);
  numbers.push(30);


  // Access by index
  let first: i32 = numbers.get(0);
  let second: i32 = numbers.get(1);


  return first + second;  // Returns 30
}

Save as arrays.zs and run:

Terminal window
zeus build arrays.zs -o arrays
./arrays
echo $?
# Output: 30

What’s Next?