GDScript Hello World: Your First Godot 4 Script

The smallest useful GDScript prints one line when its node starts:

extends Node

func _ready():
	print("Hello, World!")

Hello, World!

Three things happen here:

• extends Node says the script controls a Node. Every script extends some class.
• func _ready(): defines the function Godot calls once the node is in the scene.
• print() writes a line to the Output panel.

Running a Script in Godot

In the Godot editor, a script does nothing on its own. You attach it to a node:

1. Create a scene with a root node (for example a Node2D).
2. Select the node, then click the script icon to attach a new script.
3. Write your code and press F6 to run the current scene.

The editor shows print() output in the Output panel at the bottom. On this page the Run button does the same thing: it puts the script on a node, runs one frame and shows what was printed.

Indentation Is the Syntax

GDScript has no braces. A block is the indented lines under a line that ends with ::

extends Node

func _ready():
	var score := 120
	if score > 100:
		print("High score!")
		print("Saving...")
	print("Done")

High score!
Saving...
Done

The two indented lines under if belong to it. print("Done") is back at the function's level, so it always runs.

Godot indents with tabs by default. Spaces are allowed, but a file must stick to one or the other. Mixing them stops the script before it runs:

Parse Error: Used tab character for indentation instead of space as used before in the file.

Comments

extends Node

## Shown in the editor's help for this variable.
var speed := 200.0

func _ready():
	# A normal comment. Godot ignores it.
	print(speed) # A comment can follow code.

200.0

# starts a comment. ## starts a documentation comment: Godot shows it when you hover the variable or look it up in the built-in help. There is no block comment syntax; select lines and press Ctrl+K to comment them all.

print, prints and printt

print() joins its arguments with nothing between them. prints() puts a space between them, and printt() a tab:

extends Node

func _ready():
	var hp := 7
	print("HP: ", hp)
	prints("HP:", hp, "of", 10)

HP: 7
HP: 7 of 10

The print and debugging page covers push_error(), print_rich() and the debugger.

Other Built-in Functions Godot Calls

_ready() is one of several virtual functions. Those that matter first:

extends Node2D

func _ready():
	print("I am in the scene")

func _process(delta):
	# every frame; delta is the time since the last frame in seconds
	position.x += 100 * delta

func _input(event):
	if event.is_action_pressed("ui_accept"):
		print("Enter or Space pressed")

_process and _input need a running game loop and a window, so this block is shown and not run.