--- layout: tour title: A Tour of Jam - Basics permalink: /tour/ progress: 25 current_chapter: 1 total_chapters: 4 chapter_title: The Basics chapter_intro: Welcome to the tour. This guide will walk you through the fundamental building blocks of Jam. By the end, you'll be ready to write your first sweet application. chapters: - number: "01" name: Basics active: true - number: "02" name: Control Flow active: false - number: "03" name: Types active: false next_chapter: url: "#" title: Control Flow & Logic description: Learn about if, else, and pattern matching. ---
01

Variables & Binding

In Jam, we use const for immutable bindings and var for mutable ones.

Using const by default helps prevent bugs where data changes unexpectedly.

If you need to change a value, use var to make it mutable.

variables.jam 
const std = import("std");

// Immutable binding
const name: str = "Strawberry";
// name = "Grape"; // Error! Cannot reassign const

// Mutable binding
var count: u8 = 10;
count = 11; // This is fine with var

std.fmt.println("Making jam!");
02

Making Functions

Functions are declared with fn. They are strictly typed, ensuring you always know what goes in and what comes out.

Return types are specified directly after the parameter list. Use return to return values from a function.

functions.jam 
fn addSugar(amount: i32) i32 {
    return amount + 10;
}

fn greet() {
    // No return type = void function
    std.fmt.println("Hello!");
}

fn main() u8 {
    greet();
    return 0;
}
03

Imports & Standard Library

Jam uses import() to bring in modules. The standard library provides common utilities.

Use std.fmt for formatting and printing, std.thread for timing and threading.

imports.jam 
const std = import("std");

fn main() u8 {
    std.fmt.println("Hello, World!");
    std.fmt.print("Waiting...");
    std.thread.sleep(1000); // 1 second
    std.fmt.println("Done!");
    return 0;
}