Introduction to Zig - Lesson 1

Zig is a general-purpose programming language that gives you full control over your code. Every Zig program starts by importing the standard library with @import("std") and defining a main function. The pub fn main() void line is the entry point where execution begins. To display text, use std.debug.print which takes a format string and an empty tuple .{}. This lesson will teach you how to write and run your first Zig programs step by step.

const std = @import("std");

pub fn main() void {
    std.debug.print("Hello, world!", .{});
}

• const std = @import("std"); brings in Zig's standard library so you can use its functions.
• pub fn main() void declares the main function that runs when the program starts.
• std.debug.print prints text to the terminal for debugging and learning.
• "Hello, world!\n" is the string to print, and \n moves to a new line.
• The empty tuple .{} provides no extra values to insert into the format string.

const std = @import("std");

pub fn main() void {
    std.debug.print("Hello from Zig!", .{});
    std.debug.print("Welcome to the language.", .{});
}

• You can call std.debug.print multiple times to print several lines.
• Each call to std.debug.print prints one line of text.
• The program runs top to bottom, so the first message prints before the second.
• Every Zig program needs a pub fn main() void to start.

const std = @import("std");

pub fn main() void {
    const msg = "Hello, world!";
    std.debug.print("{s}", .{msg});
}

• const msg = "Hello, world!"; stores the message in a constant variable.
• {s} in the format string is a placeholder for a string value.
• .{msg} passes the variable msg to fill the placeholder.
• Using variables makes your code easier to change later.

const std = @import("std");

pub fn main() void {
    const name = "Zig";
    const year = 2024;
    std.debug.print("Hello {s} in {d}!", .{ name, year });
}

• You can use multiple placeholders like {s} for strings and {d} for numbers.
• The tuple .{ name, year } provides values in the same order as the placeholders.
• const declares a variable that cannot change after it is set.
• Zig uses {s} for strings and {d} for integers in format strings.

const std = @import("std");

fn greet() void {
    std.debug.print("Greetings from Zig!", .{});
}

pub fn main() void {
    greet();
}

• A function is defined with fn functionName() void { ... }.
• greet() is a custom function that prints a message when called.
• The main function calls greet() to run its code.
• Functions help you organise code into reusable pieces.

const std = @import("std");

pub fn main() void {
    std.debug.print("Hello, {s}!", .{"world"});
}

• std.io.getStdOut().writer() gets a writer for the standard output.
• The writer.print() method prints formatted text like std.debug.print.
• catch {} handles any errors that might occur during printing.
• This is a more advanced way to print that is used in larger Zig programs.