GDScript reference

GDScript is a high-level, object-oriented, imperative, and gradually typed programming language built for Godot.

GDScript is a high-level, dynamically typed programming language used to create content. It uses an indentation-based syntax similar to languages like Python. Its goal is to be optimized for and tightly integrated with Godot Engine, allowing great flexibility for content creation and integration.

GDScript is entirely independent from Python and is not based on it.

History

Note

Documentation about GDScript's history has been moved to the Frequently Asked Questions.

Example of GDScript

Some people can learn better by taking a look at the syntax, so here's an example of how GDScript looks.

# Everything after "#" is a comment.
# A file is a class!

# (optional) class definition:
class_name MyClass

# Inheritance:
extends BaseClass

# (optional) icon to show in the editor dialogs:
@icon("res://path/to/optional/icon.svg")


# Member variables.
var a = 5
var s = "Hello"
var arr = [1, 2, 3]
var dict = {"key": "value", 2: 3}
var other_dict = {key = "value", other_key = 2}
var typed_var: int
var inferred_type := "String"

# Constants.
const ANSWER = 42
const THE_NAME = "Charly"

# Enums.
enum {UNIT_NEUTRAL, UNIT_ENEMY, UNIT_ALLY}
enum Named {THING_1, THING_2, ANOTHER_THING = -1}

# Built-in vector types.
var v2 = Vector2(1, 2)
var v3 = Vector3(1, 2, 3)


# Functions.
func some_function(param1, param2, param3):
    const local_const = 5

    if param1 < local_const:
        print(param1)
    elif param2 > 5:
        print(param2)
    else:
        print("Fail!")

    for i in range(20):
        print(i)

    while param2 != 0:
        param2 -= 1

    match param3:
        3:
            print("param3 is 3!")
        _:
            print("param3 is not 3!")

    var local_var = param1 + 3
    return local_var


# Functions override functions with the same name on the base/super class.
# If you still want to call them, use "super":
func something(p1, p2):
    super(p1, p2)


# It's also possible to call another function in the super class:
func other_something(p1, p2):
    super.something(p1, p2)


# Inner class
class Something:
    var a = 10


# Constructor
func _init():
    print("Constructed!")
    var lv = Something.new()
    print(lv.a)

If you have previous experience with statically typed languages such as C, C++, or C# but never used a dynamically typed one before, it is advised you read this tutorial: GDScript: An introduction to dynamic languages.

Language

In the following, an overview is given to GDScript. Details, such as which methods are available to arrays or other objects, should be looked up in the linked class descriptions.

Identifiers

Any string that restricts itself to alphabetic characters (a to z and A to Z), digits (0 to 9) and _ qualifies as an identifier. Additionally, identifiers must not begin with a digit. Identifiers are case-sensitive (foo is different from FOO).

Keywords

The following is the list of keywords supported by the language. Since keywords are reserved words (tokens), they can't be used as identifiers. Operators (like in, not, and or or) and names of built-in types as listed in the following sections are also reserved.

Keywords are defined in the GDScript tokenizer in case you want to take a look under the hood.

Keyword

Description

if

See if/else/elif.

elif

See if/else/elif.

else

See if/else/elif.

for

See for.

while

See while.

match

See match.

break

Exits the execution of the current for or while loop.

continue

Immediately skips to the next iteration of the for or while loop. Stops execution in match and looks for a match in patterns below it

pass

Used where a statement is required syntactically but execution of code is undesired, e.g. in empty functions.

return

Returns a value from a function.

class

Defines a class.

class_name

Defines the script as a globally accessible class with the specified name.

extends

Defines what class to extend with the current class.

is

Tests whether a variable extends a given class, or is of a given built-in type.

as

Cast the value to a given type if possible.

self

Refers to current class instance.

signal

Defines a signal.

func

Defines a function.

static

Defines a static function. Static member variables are not allowed.

const

Defines a constant.

enum

Defines an enum.

var

Defines a variable.

breakpoint

Editor helper for debugger breakpoints.

preload

Preloads a class or variable. See Classes as resources.

await

Waits for a signal or a coroutine to finish. See Awaiting for signals.

yield

Previously used for coroutines. Kept as keyword for transition.

assert

Asserts a condition, logs error on failure. Ignored in non-debug builds. See Assert keyword.

void

Used to represent that a function does not return any value.

PI

PI constant.

TAU

TAU constant.

INF

Infinity constant. Used for comparisons and as result of calculations.

NAN

NAN (not a number) constant. Used as impossible result from calculations.

Operators

The following is the list of supported operators and their precedence.

Operator

Description

x[index]

Subscription (highest priority)

x.attribute

Attribute reference

foo()

Function call

is

Instance type checker

**

Power operator

Multiplies value by itself x times, similar to calling pow built-in function

~

Bitwise NOT

-x

Negative / Unary negation

* / %

Multiplication / Division / Remainder

These operators have the same behavior as C++. Integer division is truncated rather than returning a fractional number, and the % operator is only available for ints (fmod for floats), and is additionally used for Format Strings

+

Addition / Concatenation of arrays

-

Subtraction

<< >>

Bit shifting

&

Bitwise AND

^

Bitwise XOR

|

Bitwise OR

< > == != >= <=

Comparisons

in

When used with the if keyword it checks if a value is within a string, list, range, dictionary, or node. When used with the for keyword it is used to iterate though the contents of a string, list, range, dictionary or node.

not

Boolean NOT

and

Boolean AND

or

Boolean OR

if x else

Ternary if/else

as

Type casting

= += -= *= /= %= **= &= |= <<= >>=

Assignment (lowest priority)

Literals

Literal

Type

45

Base 10 integer

0x8f51

Base 16 (hexadecimal) integer

0b101010

Base 2 (binary) integer

3.14, 58.1e-10

Floating-point number (real)

"Hello", "Hi"

Strings

"""Hello"""

Multiline string

&"name"

StringName

^"Node/Label"

NodePath

$NodePath

Shorthand for get_node("NodePath")

Integers and floats can have their numbers separated with _ to make them more readable. The following ways to write numbers are all valid:

12_345_678  # Equal to 12345678.
3.141_592_7  # Equal to 3.1415927.
0x8080_0000_ffff  # Equal to 0x80800000ffff.
0b11_00_11_00  # Equal to 0b11001100.

Annotations

There are some special tokens in GDScript that act like keywords but are not, they are annotations instead. Every annotation start with the @ character and is specified by a name.

Those affect how the script is treated by external tools and usually don't change the behavior.

For instance, you can use it to export a value to the editor:

@export_range(1, 100, 1, "or_greater")
var ranged_var: int = 50

Annotations can be specified one per line or all in the same line. They affect the next statement that isn't an annotation. Annotations can have arguments sent between parentheses and separated by commas.

Both of these are the same:

@onready
@export_node_path(TextEdit, LineEdit)
var input_field

@onready @export_node_path(TextEdit, LineEdit) var input_field

Here's the list of available annotations:

Annotation

Description

@tool

Enable the Tool mode.

@onready

Defer initialization of variable until the node is in the tree. See @onready annotation.

@icon(path)

Set the class icon to show in editor. To be used together with the class_name keyword.

@rpc

RPC modifiers. See high-level multiplayer docs.

@export

@export_enum

@export_file

@export_dir

@export_global_file

@export_global_dir

@export_multiline

@export_placeholder

@export_range

@export_exp_easing

@export_color_no_alpha

@export_node_path

@export_flags

@export_flags_2d_render

@export_flags_2d_physics

@export_flags_3d_render

@export_flags_3d_physics

Export hints for the editor. See GDScript exports.

Comments

Anything from a # to the end of the line is ignored and is considered a comment.

# This is a comment.

Line continuation

A line of code in GDScript can be continued on the next line by using a backslash (\). Add one at the end of a line and the code on the next line will act like it's where the backslash is. Here is an example:

var a = 1 + \
2

A line can be continued multiple times like this:

var a = 1 + \
4 + \
10 + \
4

Built-in types

Built-in types are stack-allocated. They are passed as values. This means a copy is created on each assignment or when passing them as arguments to functions. The only exceptions are Arrays and Dictionaries, which are passed by reference so they are shared. (Packed arrays such as PackedByteArray are still passed as values.)

Basic built-in types

A variable in GDScript can be assigned to several built-in types.

null

null is an empty data type that contains no information and can not be assigned any other value.

bool

Short for "boolean", it can only contain true or false.

int

Short for "integer", it stores whole numbers (positive and negative). It is stored as a 64-bit value, equivalent to "int64_t" in C++.

float

Stores real numbers, including decimals, using floating-point values. It is stored as a 64-bit value, equivalent to "double" in C++. Note: Currently, data structures such as Vector2, Vector3, and PackedFloat32Array store 32-bit single-precision "float" values.

String

A sequence of characters in Unicode format. Strings can contain the following escape sequences:

Escape sequence

Expands to

\n

Newline (line feed)

\t

Horizontal tab character

\r

Carriage return

\a

Alert (beep/bell)

\b

Backspace

\f

Formfeed page break

\v

Vertical tab character

\"

Double quote

\'

Single quote

\\

Backslash

\uXXXX

Unicode codepoint XXXX (hexadecimal, case-insensitive)

Also, using \ followed by a newline inside a string will allow you to continue it in the next line, without inserting a newline character in the string itself.

GDScript also supports GDScript format strings.

StringName

An immutable string that allows only one instance of each name. They are slower to create and may result in waiting for locks when multithreading. In exchange, they're very fast to compare, which makes them good candidates for dictionary keys.

NodePath

A pre-parsed path to a node or a node property. They are useful to interact with the tree to get a node, or affecting properties like with Tweens.

Vector built-in types

Vector2

2D vector type containing x and y fields. Can also be accessed as an array.

Vector2i

Same as a Vector2 but the components are integers. Useful for representing items in a 2D grid.

Rect2

2D Rectangle type containing two vectors fields: position and size. Also contains an end field which is position + size.

Vector3

3D vector type containing x, y and z fields. This can also be accessed as an array.

Vector3i

Same as Vector3 but the components are integers. Can be use for indexing items in a 3D grid.

Transform2D

3×2 matrix used for 2D transforms.

Plane

3D Plane type in normalized form that contains a normal vector field and a d scalar distance.

Quat

Quaternion is a datatype used for representing a 3D rotation. It's useful for interpolating rotations.

AABB

Axis-aligned bounding box (or 3D box) contains 2 vectors fields: position and size. Also contains an end field which is position + size.

Basis

3x3 matrix used for 3D rotation and scale. It contains 3 vector fields (x, y and z) and can also be accessed as an array of 3D vectors.

Transform3D

3D Transform contains a Basis field basis and a Vector3 field origin.

Engine built-in types

Color

Color data type contains r, g, b, and a fields. It can also be accessed as h, s, and v for hue/saturation/value.

NodePath

Compiled path to a node used mainly in the scene system. It can be easily assigned to, and from, a String.

RID

Resource ID (RID). Servers use generic RIDs to reference opaque data.

Object

Base class for anything that is not a built-in type.

Container built-in types

Array

Generic sequence of arbitrary object types, including other arrays or dictionaries (see below). The array can resize dynamically. Arrays are indexed starting from index 0. Negative indices count from the end.

var arr = []
arr = [1, 2, 3]
var b = arr[1] # This is 2.
var c = arr[arr.size() - 1] # This is 3.
var d = arr[-1] # Same as the previous line, but shorter.
arr[0] = "Hi!" # Replacing value 1 with "Hi!".
arr.append(4) # Array is now ["Hi!", 2, 3, 4].

GDScript arrays are allocated linearly in memory for speed. Large arrays (more than tens of thousands of elements) may however cause memory fragmentation. If this is a concern, special types of arrays are available. These only accept a single data type. They avoid memory fragmentation and use less memory, but are atomic and tend to run slower than generic arrays. They are therefore only recommended to use for large data sets:

Dictionary

Associative container which contains values referenced by unique keys.

var d = {4: 5, "A key": "A value", 28: [1, 2, 3]}
d["Hi!"] = 0
d = {
    22: "value",
    "some_key": 2,
    "other_key": [2, 3, 4],
    "more_key": "Hello"
}

Lua-style table syntax is also supported. Lua-style uses = instead of : and doesn't use quotes to mark string keys (making for slightly less to write). However, keys written in this form can't start with a digit (like any GDScript identifier).

var d = {
    test22 = "value",
    some_key = 2,
    other_key = [2, 3, 4],
    more_key = "Hello"
}

To add a key to an existing dictionary, access it like an existing key and assign to it:

var d = {} # Create an empty Dictionary.
d.waiting = 14 # Add String "waiting" as a key and assign the value 14 to it.
d[4] = "hello" # Add integer 4 as a key and assign the String "hello" as its value.
d["Godot"] = 3.01 # Add String "Godot" as a key and assign the value 3.01 to it.

var test = 4
# Prints "hello" by indexing the dictionary with a dynamic key.
# This is not the same as `d.test`. The bracket syntax equivalent to
# `d.test` is `d["test"]`.
print(d[test])

Note

The bracket syntax can be used to access properties of any Object, not just Dictionaries. Keep in mind it will cause a script error when attempting to index a non-existing property. To avoid this, use the Object.get() and Object.set() methods instead.

Signal

A signal is a message that can be emitted by an object to those who want to listen to it. The Signal type can be used for passing the emitter around.

Signals are better used by getting them from actual objects, e.g. $Button.button_up.

Callable

Contains an object and a function, which is useful for passing functions as values (e.g. when connecting to signals).

Getting a method as a member returns a callable.``var x = $Sprite2D.rotate`` will set the value of x to a callable with $Sprite2D as the object and rotate as the method.

You can call it using the call method: x.call(PI).

Data

Variables

Variables can exist as class members or local to functions. They are created with the var keyword and may, optionally, be assigned a value upon initialization.

var a # Data type is 'null' by default.
var b = 5
var c = 3.8
var d = b + c # Variables are always initialized in order.

Variables can optionally have a type specification. When a type is specified, the variable will be forced to have always that same type, and trying to assign an incompatible value will raise an error.

Types are specified in the variable declaration using a : (colon) symbol after the variable name, followed by the type.

var my_vector2: Vector2
var my_node: Node = Sprite2D.new()

If the variable is initialized within the declaration, the type can be inferred, so it's possible to omit the type name:

var my_vector2 := Vector2() # 'my_vector2' is of type 'Vector2'.
var my_node := Sprite2D.new() # 'my_node' is of type 'Sprite2D'.

Type inference is only possible if the assigned value has a defined type, otherwise it will raise an error.

Valid types are:

  • Built-in types (Array, Vector2, int, String, etc.).

  • Engine classes (Node, Resource, Reference, etc.).

  • Constant names if they contain a script resource (MyScript if you declared const MyScript = preload("res://my_script.gd")).

  • Other classes in the same script, respecting scope (InnerClass.NestedClass if you declared class NestedClass inside the class InnerClass in the same scope).

  • Script classes declared with the class_name keyword.

  • Autoloads registered as singletons.

Casting

Values assigned to typed variables must have a compatible type. If it's needed to coerce a value to be of a certain type, in particular for object types, you can use the casting operator as.

Casting between object types results in the same object if the value is of the same type or a subtype of the cast type.

var my_node2D: Node2D
my_node2D = $Sprite2D as Node2D # Works since Sprite2D is a subtype of Node2D.

If the value is not a subtype, the casting operation will result in a null value.

var my_node2D: Node2D
my_node2D = $Button as Node2D # Results in 'null' since a Button is not a subtype of Node2D.

For built-in types, they will be forcibly converted if possible, otherwise the engine will raise an error.

var my_int: int
my_int = "123" as int # The string can be converted to int.
my_int = Vector2() as int # A Vector2 can't be converted to int, this will cause an error.

Casting is also useful to have better type-safe variables when interacting with the scene tree:

# Will infer the variable to be of type Sprite2D.
var my_sprite := $Character as Sprite2D

# Will fail if $AnimPlayer is not an AnimationPlayer, even if it has the method 'play()'.
($AnimPlayer as AnimationPlayer).play("walk")

Constants

Constants are values you cannot change when the game is running. Their value must be known at compile-time. Using the const keyword allows you to give a constant value a name. Trying to assign a value to a constant after it's declared will give you an error.

We recommend using constants whenever a value is not meant to change.

const A = 5
const B = Vector2(20, 20)
const C = 10 + 20 # Constant expression.
const D = Vector2(20, 30).x # Constant expression: 20.
const E = [1, 2, 3, 4][0] # Constant expression: 1.
const F = sin(20) # 'sin()' can be used in constant expressions.
const G = x + 20 # Invalid; this is not a constant expression!
const H = A + 20 # Constant expression: 25 (`A` is a constant).

Although the type of constants is inferred from the assigned value, it's also possible to add explicit type specification:

const A: int = 5
const B: Vector2 = Vector2()

Assigning a value of an incompatible type will raise an error.

You can also create constants inside a function, which is useful to name local magic values.

Note

Since objects, arrays and dictionaries are passed by reference, constants are "flat". This means that if you declare a constant array or dictionary, it can still be modified afterwards. They can't be reassigned with another value though.

Enums

Enums are basically a shorthand for constants, and are pretty useful if you want to assign consecutive integers to some constant.

If you pass a name to the enum, it will put all the keys inside a constant dictionary of that name.

Important

In Godot 3.1 and later, keys in a named enum are not registered as global constants. They should be accessed prefixed by the enum's name (Name.KEY); see an example below.

enum {TILE_BRICK, TILE_FLOOR, TILE_SPIKE, TILE_TELEPORT}
# Is the same as:
const TILE_BRICK = 0
const TILE_FLOOR = 1
const TILE_SPIKE = 2
const TILE_TELEPORT = 3

enum State {STATE_IDLE, STATE_JUMP = 5, STATE_SHOOT}
# Is the same as:
const State = {STATE_IDLE = 0, STATE_JUMP = 5, STATE_SHOOT = 6}
# Access values with State.STATE_IDLE, etc.

Functions

Functions always belong to a class. The scope priority for variable look-up is: local → class member → global. The self variable is always available and is provided as an option for accessing class members, but is not always required (and should not be sent as the function's first argument, unlike Python).

func my_function(a, b):
    print(a)
    print(b)
    return a + b  # Return is optional; without it 'null' is returned.

A function can return at any point. The default return value is null.

Functions can also have type specification for the arguments and for the return value. Types for arguments can be added in a similar way to variables:

func my_function(a: int, b: String):
    pass

If a function argument has a default value, it's possible to infer the type:

func my_function(int_arg := 42, String_arg := "string"):
    pass

The return type of the function can be specified after the arguments list using the arrow token (->):

func my_int_function() -> int:
    return 0

Functions that have a return type must return a proper value. Setting the type as void means the function doesn't return anything. Void functions can return early with the return keyword, but they can't return any value.

func void_function() -> void:
    return # Can't return a value.

Note

Non-void functions must always return a value, so if your code has branching statements (such as an if/else construct), all the possible paths must have a return. E.g., if you have a return inside an if block but not after it, the editor will raise an error because if the block is not executed, the function won't have a valid value to return.

Referencing functions

Functions are first-class items in terms of the Callable object. Referencing a function by name without calling it will automatically generate the proper callable. This can be used to pass functions as arguments.

func map(arr: Array, function: Callable) -> Array:
    var result = []
    for item in arr:
        result.push_back(function.call(item))
    return result

func add1(value: int) -> int:
    return value + 1;

func _ready() -> void:
    var my_array = [1, 2, 3]
    var plus_one = map(my_array, add1)
    print(plus_one) # Prints [2, 3, 4].

Note

Callables must be called with the call method. You cannot use the () operator directly. This behavior is implemented to avoid performance issues on direct function calls.

Static functions

A function can be declared static. When a function is static, it has no access to the instance member variables or self. This is mainly useful to make libraries of helper functions:

static func sum2(a, b):
    return a + b

Statements and control flow

Statements are standard and can be assignments, function calls, control flow structures, etc (see below). ; as a statement separator is entirely optional.

Expressions

Expressions are sequences of operators and their operands in orderly fashion. An expression by itself can be a statement too, though only calls are reasonable to use as statements since other expressions don't have side effects.

Expressions return values that can be assigned to valid targets. Operands to some operator can be another expression. An assignment is not an exp