godot/doc/classes/Array.xml
2024-09-15 15:52:50 +08:00

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XML

<?xml version="1.0" encoding="UTF-8" ?>
<class name="Array" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
<brief_description>
A built-in data structure that holds a sequence of elements.
</brief_description>
<description>
An array data structure that can contain a sequence of elements of any [Variant] type. Elements are accessed by a numerical index starting at [code]0[/code]. Negative indices are used to count from the back ([code]-1[/code] is the last element, [code]-2[/code] is the second to last, etc.).
[codeblocks]
[gdscript]
var array = ["First", 2, 3, "Last"]
print(array[0]) # Prints "First"
print(array[2]) # Prints 3
print(array[-1]) # Prints "Last"
array[1] = "Second"
print(array[1]) # Prints "Second"
print(array[-3]) # Prints "Second"
[/gdscript]
[csharp]
var array = new Godot.Collections.Array{"First", 2, 3, "Last"};
GD.Print(array[0]); // Prints "First"
GD.Print(array[2]); // Prints 3
GD.Print(array[array.Count - 1]); // Prints "Last"
array[2] = "Second";
GD.Print(array[1]); // Prints "Second"
GD.Print(array[array.Count - 3]); // Prints "Second"
[/csharp]
[/codeblocks]
[b]Note:[/b] Arrays are always passed by [b]reference[/b]. To get a copy of an array that can be modified independently of the original array, use [method duplicate].
[b]Note:[/b] Erasing elements while iterating over arrays is [b]not[/b] supported and will result in unpredictable behavior.
[b]Differences between packed arrays, typed arrays, and untyped arrays:[/b] Packed arrays are generally faster to iterate on and modify compared to a typed array of the same type (e.g. [PackedInt64Array] versus [code]Array[int][/code]). Also, packed arrays consume less memory. As a downside, packed arrays are less flexible as they don't offer as many convenience methods such as [method Array.map]. Typed arrays are in turn faster to iterate on and modify than untyped arrays.
</description>
<tutorials>
</tutorials>
<constructors>
<constructor name="Array">
<return type="Array" />
<description>
Constructs an empty [Array].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="base" type="Array" />
<param index="1" name="type" type="int" />
<param index="2" name="class_name" type="StringName" />
<param index="3" name="script" type="Variant" />
<description>
Creates a typed array from the [param base] array. A typed array can only contain elements of the given type, or that inherit from the given class, as described by this constructor's parameters:
- [param type] is the built-in [Variant] type, as one the [enum Variant.Type] constants.
- [param class_name] is the built-in class name (see [method Object.get_class]).
- [param script] is the associated script. It must be a [Script] instance or [code]null[/code].
If [param type] is not [constant TYPE_OBJECT], [param class_name] must be an empty [StringName] and [param script] must be [code]null[/code].
[codeblock]
class_name Sword
extends Node
class Stats:
pass
func _ready():
var a = Array([], TYPE_INT, "", null) # Array[int]
var b = Array([], TYPE_OBJECT, "Node", null) # Array[Node]
var c = Array([], TYPE_OBJECT, "Node", Sword) # Array[Sword]
var d = Array([], TYPE_OBJECT, "RefCounted", Stats) # Array[Stats]
[/codeblock]
The [param base] array's elements are converted when necessary. If this is not possible or [param base] is already typed, this constructor fails and returns an empty [Array].
In GDScript, this constructor is usually not necessary, as it is possible to create a typed array through static typing:
[codeblock]
var numbers: Array[float] = []
var children: Array[Node] = [$Node, $Sprite2D, $RigidBody3D]
var integers: Array[int] = [0.2, 4.5, -2.0]
print(integers) # Prints [0, 4, -2]
[/codeblock]
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="Array" />
<description>
Returns the same array as [param from]. If you need a copy of the array, use [method duplicate].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedByteArray" />
<description>
Constructs an array from a [PackedByteArray].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedColorArray" />
<description>
Constructs an array from a [PackedColorArray].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedFloat32Array" />
<description>
Constructs an array from a [PackedFloat32Array].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedFloat64Array" />
<description>
Constructs an array from a [PackedFloat64Array].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedInt32Array" />
<description>
Constructs an array from a [PackedInt32Array].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedInt64Array" />
<description>
Constructs an array from a [PackedInt64Array].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedStringArray" />
<description>
Constructs an array from a [PackedStringArray].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedVector2Array" />
<description>
Constructs an array from a [PackedVector2Array].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedVector3Array" />
<description>
Constructs an array from a [PackedVector3Array].
</description>
</constructor>
<constructor name="Array">
<return type="Array" />
<param index="0" name="from" type="PackedVector4Array" />
<description>
Constructs an array from a [PackedVector4Array].
</description>
</constructor>
</constructors>
<methods>
<method name="all" qualifiers="const">
<return type="bool" />
<param index="0" name="method" type="Callable" />
<description>
Calls the given [Callable] on each element in the array and returns [code]true[/code] if the [Callable] returns [code]true[/code] for [i]all[/i] elements in the array. If the [Callable] returns [code]false[/code] for one array element or more, this method returns [code]false[/code].
The [param method] should take one [Variant] parameter (the current array element) and return a [bool].
[codeblocks]
[gdscript]
func greater_than_5(number):
return number &gt; 5
func _ready():
print([6, 10, 6].all(greater_than_5)) # Prints true (3/3 elements evaluate to true).
print([4, 10, 4].all(greater_than_5)) # Prints false (1/3 elements evaluate to true).
print([4, 4, 4].all(greater_than_5)) # Prints false (0/3 elements evaluate to true).
print([].all(greater_than_5)) # Prints true (0/0 elements evaluate to true).
# Same as the first line above, but using a lambda function.
print([6, 10, 6].all(func(element): return element &gt; 5)) # Prints true
[/gdscript]
[csharp]
private static bool GreaterThan5(int number)
{
return number &gt; 5;
}
public override void _Ready()
{
// Prints true (3/3 elements evaluate to true).
GD.Print(new Godot.Collections.Array&gt;int&lt; { 6, 10, 6 }.All(GreaterThan5));
// Prints false (1/3 elements evaluate to true).
GD.Print(new Godot.Collections.Array&gt;int&lt; { 4, 10, 4 }.All(GreaterThan5));
// Prints false (0/3 elements evaluate to true).
GD.Print(new Godot.Collections.Array&gt;int&lt; { 4, 4, 4 }.All(GreaterThan5));
// Prints true (0/0 elements evaluate to true).
GD.Print(new Godot.Collections.Array&gt;int&lt; { }.All(GreaterThan5));
// Same as the first line above, but using a lambda function.
GD.Print(new Godot.Collections.Array&gt;int&lt; { 6, 10, 6 }.All(element =&gt; element &gt; 5)); // Prints true
}
[/csharp]
[/codeblocks]
See also [method any], [method filter], [method map] and [method reduce].
[b]Note:[/b] Unlike relying on the size of an array returned by [method filter], this method will return as early as possible to improve performance (especially with large arrays).
[b]Note:[/b] For an empty array, this method [url=https://en.wikipedia.org/wiki/Vacuous_truth]always[/url] returns [code]true[/code].
</description>
</method>
<method name="any" qualifiers="const">
<return type="bool" />
<param index="0" name="method" type="Callable" />
<description>
Calls the given [Callable] on each element in the array and returns [code]true[/code] if the [Callable] returns [code]true[/code] for [i]one or more[/i] elements in the array. If the [Callable] returns [code]false[/code] for all elements in the array, this method returns [code]false[/code].
The [param method] should take one [Variant] parameter (the current array element) and return a [bool].
[codeblock]
func greater_than_5(number):
return number &gt; 5
func _ready():
print([6, 10, 6].any(greater_than_5)) # Prints true (3 elements evaluate to true).
print([4, 10, 4].any(greater_than_5)) # Prints true (1 elements evaluate to true).
print([4, 4, 4].any(greater_than_5)) # Prints false (0 elements evaluate to true).
print([].any(greater_than_5)) # Prints false (0 elements evaluate to true).
# Same as the first line above, but using a lambda function.
print([6, 10, 6].any(func(number): return number &gt; 5)) # Prints true
[/codeblock]
See also [method all], [method filter], [method map] and [method reduce].
[b]Note:[/b] Unlike relying on the size of an array returned by [method filter], this method will return as early as possible to improve performance (especially with large arrays).
[b]Note:[/b] For an empty array, this method always returns [code]false[/code].
</description>
</method>
<method name="append">
<return type="void" />
<param index="0" name="value" type="Variant" />
<description>
Appends [param value] at the end of the array (alias of [method push_back]).
</description>
</method>
<method name="append_array">
<return type="void" />
<param index="0" name="array" type="Array" />
<description>
Appends another [param array] at the end of this array.
[codeblock]
var numbers = [1, 2, 3]
var extra = [4, 5, 6]
numbers.append_array(extra)
print(numbers) # Prints [1, 2, 3, 4, 5, 6]
[/codeblock]
</description>
</method>
<method name="assign">
<return type="void" />
<param index="0" name="array" type="Array" />
<description>
Assigns elements of another [param array] into the array. Resizes the array to match [param array]. Performs type conversions if the array is typed.
</description>
</method>
<method name="back" qualifiers="const">
<return type="Variant" />
<description>
Returns the last element of the array. If the array is empty, fails and returns [code]null[/code]. See also [method front].
[b]Note:[/b] Unlike with the [code][][/code] operator ([code]array[-1][/code]), an error is generated without stopping project execution.
</description>
</method>
<method name="bsearch" qualifiers="const">
<return type="int" />
<param index="0" name="value" type="Variant" />
<param index="1" name="before" type="bool" default="true" />
<description>
Returns the index of [param value] in the sorted array. If it cannot be found, returns where [param value] should be inserted to keep the array sorted. The algorithm used is [url=https://en.wikipedia.org/wiki/Binary_search_algorithm]binary search[/url].
If [param before] is [code]true[/code] (as by default), the returned index comes before all existing elements equal to [param value] in the array.
[codeblock]
var numbers = [2, 4, 8, 10]
var idx = numbers.bsearch(7)
numbers.insert(idx, 7)
print(numbers) # Prints [2, 4, 7, 8, 10]
var fruits = ["Apple", "Lemon", "Lemon", "Orange"]
print(fruits.bsearch("Lemon", true)) # Prints 1, points at the first "Lemon".
print(fruits.bsearch("Lemon", false)) # Prints 3, points at "Orange".
[/codeblock]
[b]Note:[/b] Calling [method bsearch] on an [i]unsorted[/i] array will result in unexpected behavior. Use [method sort] before calling this method.
</description>
</method>
<method name="bsearch_custom" qualifiers="const">
<return type="int" />
<param index="0" name="value" type="Variant" />
<param index="1" name="func" type="Callable" />
<param index="2" name="before" type="bool" default="true" />
<description>
Returns the index of [param value] in the sorted array. If it cannot be found, returns where [param value] should be inserted to keep the array sorted (using [param func] for the comparisons). The algorithm used is [url=https://en.wikipedia.org/wiki/Binary_search_algorithm]binary search[/url].
Similar to [method sort_custom], [param func] is called as many times as necessary, receiving one array element and [param value] as arguments. The function should return [code]true[/code] if the array element should be [i]behind[/i] [param value], otherwise it should return [code]false[/code].
If [param before] is [code]true[/code] (as by default), the returned index comes before all existing elements equal to [param value] in the array.
[codeblock]
func sort_by_amount(a, b):
if a[1] &lt; b[1]:
return true
return false
func _ready():
var my_items = [["Tomato", 2], ["Kiwi", 5], ["Rice", 9]]
var apple = ["Apple", 5]
# "Apple" is inserted before "Kiwi".
my_items.insert(my_items.bsearch_custom(apple, sort_by_amount, true), apple)
var banana = ["Banana", 5]
# "Banana" is inserted after "Kiwi".
my_items.insert(my_items.bsearch_custom(banana, sort_by_amount, false), banana)
# Prints [["Tomato", 2], ["Apple", 5], ["Kiwi", 5], ["Banana", 5], ["Rice", 9]]
print(my_items)
[/codeblock]
[b]Note:[/b] Calling [method bsearch_custom] on an [i]unsorted[/i] array will result in unexpected behavior. Use [method sort_custom] with [param func] before calling this method.
</description>
</method>
<method name="clear">
<return type="void" />
<description>
Removes all elements from the array. This is equivalent to using [method resize] with a size of [code]0[/code].
</description>
</method>
<method name="count" qualifiers="const">
<return type="int" />
<param index="0" name="value" type="Variant" />
<description>
Returns the number of times an element is in the array.
</description>
</method>
<method name="duplicate" qualifiers="const">
<return type="Array" />
<param index="0" name="deep" type="bool" default="false" />
<description>
Returns a new copy of the array.
By default, a [b]shallow[/b] copy is returned: all nested [Array] and [Dictionary] elements are shared with the original array. Modifying them in one array will also affect them in the other.[br]If [param deep] is [code]true[/code], a [b]deep[/b] copy is returned: all nested arrays and dictionaries are also duplicated (recursively).
</description>
</method>
<method name="erase">
<return type="void" />
<param index="0" name="value" type="Variant" />
<description>
Finds and removes the first occurrence of [param value] from the array. If [param value] does not exist in the array, nothing happens. To remove an element by index, use [method remove_at] instead.
[b]Note:[/b] This method shifts every element's index after the removed [param value] back, which may have a noticeable performance cost, especially on larger arrays.
[b]Note:[/b] Erasing elements while iterating over arrays is [b]not[/b] supported and will result in unpredictable behavior.
</description>
</method>
<method name="fill">
<return type="void" />
<param index="0" name="value" type="Variant" />
<description>
Assigns the given [param value] to all elements in the array.
This method can often be combined with [method resize] to create an array with a given size and initialized elements:
[codeblocks]
[gdscript]
var array = []
array.resize(5)
array.fill(2)
print(array) # Prints [2, 2, 2, 2, 2]
[/gdscript]
[csharp]
var array = new Godot.Collections.Array();
array.Resize(5);
array.Fill(2);
GD.Print(array); // Prints [2, 2, 2, 2, 2]
[/csharp]
[/codeblocks]
[b]Note:[/b] If [param value] is a [Variant] passed by reference ([Object]-derived, [Array], [Dictionary], etc.), the array will be filled with references to the same [param value], which are not duplicates.
</description>
</method>
<method name="filter" qualifiers="const">
<return type="Array" />
<param index="0" name="method" type="Callable" />
<description>
Calls the given [Callable] on each element in the array and returns a new, filtered [Array].
The [param method] receives one of the array elements as an argument, and should return [code]true[/code] to add the element to the filtered array, or [code]false[/code] to exclude it.
[codeblock]
func is_even(number):
return number % 2 == 0
func _ready():
print([1, 4, 5, 8].filter(is_even)) # Prints [4, 8]
# Same as above, but using a lambda function.
print([1, 4, 5, 8].filter(func(number): return number % 2 == 0))
[/codeblock]
See also [method any], [method all], [method map] and [method reduce].
</description>
</method>
<method name="find" qualifiers="const">
<return type="int" />
<param index="0" name="what" type="Variant" />
<param index="1" name="from" type="int" default="0" />
<description>
Returns the index of the [b]first[/b] occurrence of [param what] in this array, or [code]-1[/code] if there are none. The search's start can be specified with [param from], continuing to the end of the array.
[b]Note:[/b] If you just want to know whether the array contains [param what], use [method has] ([code]Contains[/code] in C#). In GDScript, you may also use the [code]in[/code] operator.
[b]Note:[/b] For performance reasons, the search is affected by [param what]'s [enum Variant.Type]. For example, [code]7[/code] ([int]) and [code]7.0[/code] ([float]) are not considered equal for this method.
</description>
</method>
<method name="front" qualifiers="const">
<return type="Variant" />
<description>
Returns the first element of the array. If the array is empty, fails and returns [code]null[/code]. See also [method back].
[b]Note:[/b] Unlike with the [code][][/code] operator ([code]array[0][/code]), an error is generated without stopping project execution.
</description>
</method>
<method name="get_typed_builtin" qualifiers="const">
<return type="int" />
<description>
Returns the built-in [Variant] type of the typed array as a [enum Variant.Type] constant. If the array is not typed, returns [constant TYPE_NIL]. See also [method is_typed].
</description>
</method>
<method name="get_typed_class_name" qualifiers="const">
<return type="StringName" />
<description>
Returns the [b]built-in[/b] class name of the typed array, if the built-in [Variant] type [constant TYPE_OBJECT]. Otherwise, returns an empty [StringName]. See also [method is_typed] and [method Object.get_class].
</description>
</method>
<method name="get_typed_script" qualifiers="const">
<return type="Variant" />
<description>
Returns the [Script] instance associated with this typed array, or [code]null[/code] if it does not exist. See also [method is_typed].
</description>
</method>
<method name="has" qualifiers="const" keywords="includes, contains">
<return type="bool" />
<param index="0" name="value" type="Variant" />
<description>
Returns [code]true[/code] if the array contains the given [param value].
[codeblocks]
[gdscript]
print(["inside", 7].has("inside")) # Prints true
print(["inside", 7].has("outside")) # Prints false
print(["inside", 7].has(7)) # Prints true
print(["inside", 7].has("7")) # Prints false
[/gdscript]
[csharp]
var arr = new Godot.Collections.Array { "inside", 7 };
// By C# convention, this method is renamed to `Contains`.
GD.Print(arr.Contains("inside")); // Prints true
GD.Print(arr.Contains("outside")); // Prints false
GD.Print(arr.Contains(7)); // Prints true
GD.Print(arr.Contains("7")); // Prints false
[/csharp]
[/codeblocks]
In GDScript, this is equivalent to the [code]in[/code] operator:
[codeblock]
if 4 in [2, 4, 6, 8]:
print("4 is here!") # Will be printed.
[/codeblock]
[b]Note:[/b] For performance reasons, the search is affected by the [param value]'s [enum Variant.Type]. For example, [code]7[/code] ([int]) and [code]7.0[/code] ([float]) are not considered equal for this method.
</description>
</method>
<method name="hash" qualifiers="const">
<return type="int" />
<description>
Returns a hashed 32-bit integer value representing the array and its contents.
[b]Note:[/b] Arrays with equal hash values are [i]not[/i] guaranteed to be the same, as a result of hash collisions. On the countrary, arrays with different hash values are guaranteed to be different.
</description>
</method>
<method name="insert">
<return type="int" />
<param index="0" name="position" type="int" />
<param index="1" name="value" type="Variant" />
<description>
Inserts a new element ([param value]) at a given index ([param position]) in the array. [param position] should be between [code]0[/code] and the array's [method size].
Returns [constant OK] on success, or one of the other [enum Error] constants if this method fails.
[b]Note:[/b] Every element's index after [param position] needs to be shifted forward, which may have a noticeable performance cost, especially on larger arrays.
</description>
</method>
<method name="is_empty" qualifiers="const">
<return type="bool" />
<description>
Returns [code]true[/code] if the array is empty ([code][][/code]). See also [method size].
</description>
</method>
<method name="is_read_only" qualifiers="const">
<return type="bool" />
<description>
Returns [code]true[/code] if the array is read-only. See [method make_read_only].
In GDScript, arrays are automatically read-only if declared with the [code]const[/code] keyword.
</description>
</method>
<method name="is_same_typed" qualifiers="const">
<return type="bool" />
<param index="0" name="array" type="Array" />
<description>
Returns [code]true[/code] if this array is typed the same as the given [param array]. See also [method is_typed].
</description>
</method>
<method name="is_typed" qualifiers="const">
<return type="bool" />
<description>
Returns [code]true[/code] if the array is typed. Typed arrays can only contain elements of a specific type, as defined by the typed array constructor. The methods of a typed array are still expected to return a generic [Variant].
In GDScript, it is possible to define a typed array with static typing:
[codeblock]
var numbers: Array[float] = [0.2, 4.2, -2.0]
print(numbers.is_typed()) # Prints true
[/codeblock]
</description>
</method>
<method name="make_read_only">
<return type="void" />
<description>
Makes the array read-only. The array's elements cannot be overridden with different values, and their order cannot change. Does not apply to nested elements, such as dictionaries.
In GDScript, arrays are automatically read-only if declared with the [code]const[/code] keyword.
</description>
</method>
<method name="map" qualifiers="const">
<return type="Array" />
<param index="0" name="method" type="Callable" />
<description>
Calls the given [Callable] for each element in the array and returns a new array filled with values returned by the [param method].
The [param method] should take one [Variant] parameter (the current array element) and can return any [Variant].
[codeblock]
func double(number):
return number * 2
func _ready():
print([1, 2, 3].map(double)) # Prints [2, 4, 6]
# Same as above, but using a lambda function.
print([1, 2, 3].map(func(element): return element * 2))
[/codeblock]
See also [method filter], [method reduce], [method any] and [method all].
</description>
</method>
<method name="max" qualifiers="const">
<return type="Variant" />
<description>
Returns the maximum value contained in the array, if all elements can be compared. Otherwise, returns [code]null[/code]. See also [method min].
To find the maximum value using a custom comparator, you can use [method reduce].
</description>
</method>
<method name="min" qualifiers="const">
<return type="Variant" />
<description>
Returns the minimum value contained in the array, if all elements can be compared. Otherwise, returns [code]null[/code]. See also [method max].
</description>
</method>
<method name="pick_random" qualifiers="const">
<return type="Variant" />
<description>
Returns a random element from the array. Generates an error and returns [code]null[/code] if the array is empty.
[codeblocks]
[gdscript]
# May print 1, 2, 3.25, or "Hi".
print([1, 2, 3.25, "Hi"].pick_random())
[/gdscript]
[csharp]
var array = new Godot.Collections.Array { 1, 2, 3.25f, "Hi" };
GD.Print(array.PickRandom()); // May print 1, 2, 3.25, or "Hi".
[/csharp]
[/codeblocks]
[b]Note:[/b] Like many similar functions in the engine (such as [method @GlobalScope.randi] or [method shuffle]), this method uses a common, global random seed. To get a predictable outcome from this method, see [method @GlobalScope.seed].
</description>
</method>
<method name="pop_at">
<return type="Variant" />
<param index="0" name="position" type="int" />
<description>
Removes and returns the element of the array at index [param position]. If negative, [param position] is considered relative to the end of the array. Returns [code]null[/code] if the array is empty. If [param position] is out of bounds, an error message is also generated.
[b]Note:[/b] This method shifts every element's index after [param position] back, which may have a noticeable performance cost, especially on larger arrays.
</description>
</method>
<method name="pop_back">
<return type="Variant" />
<description>
Removes and returns the last element of the array. Returns [code]null[/code] if the array is empty, without generating an error. See also [method pop_front].
</description>
</method>
<method name="pop_front">
<return type="Variant" />
<description>
Removes and returns the first element of the array. Returns [code]null[/code] if the array is empty, without generating an error. See also [method pop_back].
[b]Note:[/b] This method shifts every other element's index back, which may have a noticeable performance cost, especially on larger arrays.
</description>
</method>
<method name="push_back">
<return type="void" />
<param index="0" name="value" type="Variant" />
<description>
Appends an element at the end of the array. See also [method push_front].
</description>
</method>
<method name="push_front">
<return type="void" />
<param index="0" name="value" type="Variant" />
<description>
Adds an element at the beginning of the array. See also [method push_back].
[b]Note:[/b] This method shifts every other element's index forward, which may have a noticeable performance cost, especially on larger arrays.
</description>
</method>
<method name="reduce" qualifiers="const">
<return type="Variant" />
<param index="0" name="method" type="Callable" />
<param index="1" name="accum" type="Variant" default="null" />
<description>
Calls the given [Callable] for each element in array, accumulates the result in [param accum], then returns it.
The [param method] takes two arguments: the current value of [param accum] and the current array element. If [param accum] is [code]null[/code] (as by default), the iteration will start from the second element, with the first one used as initial value of [param accum].
[codeblock]
func sum(accum, number):
return accum + number
func _ready():
print([1, 2, 3].reduce(sum, 0)) # Prints 6
print([1, 2, 3].reduce(sum, 10)) # Prints 16
# Same as above, but using a lambda function.
print([1, 2, 3].reduce(func(accum, number): return accum + number, 10))
[/codeblock]
If [method max] is not desirable, this method may also be used to implement a custom comparator:
[codeblock]
func _ready():
var arr = [Vector2(5, 0), Vector2(3, 4), Vector2(1, 2)]
var longest_vec = arr.reduce(func(max, vec): return vec if is_length_greater(vec, max) else max)
print(longest_vec) # Prints Vector2(3, 4).
func is_length_greater(a, b):
return a.length() &gt; b.length()
[/codeblock]
See also [method map], [method filter], [method any] and [method all].
</description>
</method>
<method name="remove_at">
<return type="void" />
<param index="0" name="position" type="int" />
<description>
Removes the element from the array at the given index ([param position]). If the index is out of bounds, this method fails.
If you need to return the removed element, use [method pop_at]. To remove an element by value, use [method erase] instead.
[b]Note:[/b] This method shifts every element's index after [param position] back, which may have a noticeable performance cost, especially on larger arrays.
[b]Note:[/b] The [param position] cannot be negative. To remove an element relative to the end of the array, use [code]arr.remove_at(arr.size() - (i + 1))[/code]. To remove the last element from the array, use [code]arr.resize(arr.size() - 1)[/code].
</description>
</method>
<method name="resize">
<return type="int" />
<param index="0" name="size" type="int" />
<description>
Sets the array's number of elements to [param size]. If [param size] is smaller than the array's current size, the elements at the end are removed. If [param size] is greater, new default elements (usually [code]null[/code]) are added, depending on the array's type.
Returns [constant OK] on success, or one of the other [enum Error] constants if this method fails.
[b]Note:[/b] Calling this method once and assigning the new values is faster than calling [method append] for every new element.
</description>
</method>
<method name="reverse">
<return type="void" />
<description>
Reverses the order of all elements in the array.
</description>
</method>
<method name="rfind" qualifiers="const">
<return type="int" />
<param index="0" name="what" type="Variant" />
<param index="1" name="from" type="int" default="-1" />
<description>
Returns the index of the [b]last[/b] occurrence of [param what] in this array, or [code]-1[/code] if there are none. The search's start can be specified with [param from], continuing to the beginning of the array. This method is the reverse of [method find].
</description>
</method>
<method name="shuffle">
<return type="void" />
<description>
Shuffles all elements of the array in a random order.
[b]Note:[/b] Like many similar functions in the engine (such as [method @GlobalScope.randi] or [method pick_random]), this method uses a common, global random seed. To get a predictable outcome from this method, see [method @GlobalScope.seed].
</description>
</method>
<method name="size" qualifiers="const">
<return type="int" />
<description>
Returns the number of elements in the array. Empty arrays ([code][][/code]) always return [code]0[/code]. See also [method is_empty].
</description>
</method>
<method name="slice" qualifiers="const">
<return type="Array" />
<param index="0" name="begin" type="int" />
<param index="1" name="end" type="int" default="2147483647" />
<param index="2" name="step" type="int" default="1" />
<param index="3" name="deep" type="bool" default="false" />
<description>
Returns a new [Array] containing this array's elements, from index [param begin] (inclusive) to [param end] (exclusive), every [param step] elements.
If either [param begin] or [param end] are negative, their value is relative to the end of the array.
If [param step] is negative, this method iterates through the array in reverse, returning a slice ordered backwards. For this to work, [param begin] must be greater than [param end].
If [param deep] is [code]true[/code], all nested [Array] and [Dictionary] elements in the slice are duplicated from the original, recursively. See also [method duplicate]).
[codeblock]
var letters = ["A", "B", "C", "D", "E", "F"]
print(letters.slice(0, 2)) # Prints ["A", "B"]
print(letters.slice(2, -2)) # Prints ["C", "D"]
print(letters.slice(-2, 6)) # Prints ["E", "F"]
print(letters.slice(0, 6, 2)) # Prints ["A", "C", "E"]
print(letters.slice(4, 1, -1)) # Prints ["E", "D", "C"]
[/codeblock]
</description>
</method>
<method name="sort">
<return type="void" />
<description>
Sorts the array in ascending order. The final order is dependent on the "less than" ([code]&lt;[/code]) comparison between elements.
[codeblocks]
[gdscript]
var numbers = [10, 5, 2.5, 8]
numbers.sort()
print(numbers) # Prints [2.5, 5, 8, 10]
[/gdscript]
[csharp]
var numbers = new Godot.Collections.Array { 10, 5, 2.5, 8 };
numbers.Sort();
GD.Print(numbers); // Prints [2.5, 5, 8, 10]
[/csharp]
[/codeblocks]
[b]Note:[/b] The sorting algorithm used is not [url=https://en.wikipedia.org/wiki/Sorting_algorithm#Stability]stable[/url]. This means that equivalent elements (such as [code]2[/code] and [code]2.0[/code]) may have their order changed when calling [method sort].
</description>
</method>
<method name="sort_custom">
<return type="void" />
<param index="0" name="func" type="Callable" />
<description>
Sorts the array using a custom [Callable].
[param func] is called as many times as necessary, receiving two array elements as arguments. The function should return [code]true[/code] if the first element should be moved [i]before[/i] the second one, otherwise it should return [code]false[/code].
[codeblock]
func sort_ascending(a, b):
if a[1] &lt; b[1]:
return true
return false
func _ready():
var my_items = [["Tomato", 5], ["Apple", 9], ["Rice", 4]]
my_items.sort_custom(sort_ascending)
print(my_items) # Prints [["Rice", 4], ["Tomato", 5], ["Apple", 9]]
# Sort descending, using a lambda function.
my_items.sort_custom(func(a, b): return a[1] &gt; b[1])
print(my_items) # Prints [["Apple", 9], ["Tomato", 5], ["Rice", 4]]
[/codeblock]
It may also be necessary to use this method to sort strings by natural order, with [method String.naturalnocasecmp_to], as in the following example:
[codeblock]
var files = ["newfile1", "newfile2", "newfile10", "newfile11"]
files.sort_custom(func(a, b): return a.naturalnocasecmp_to(b) &lt; 0)
print(files) # Prints ["newfile1", "newfile2", "newfile10", "newfile11"]
[/codeblock]
[b]Note:[/b] In C#, this method is not supported.
[b]Note:[/b] The sorting algorithm used is not [url=https://en.wikipedia.org/wiki/Sorting_algorithm#Stability]stable[/url]. This means that values considered equal may have their order changed when calling this method.
[b]Note:[/b] You should not randomize the return value of [param func], as the heapsort algorithm expects a consistent result. Randomizing the return value will result in unexpected behavior.
</description>
</method>
</methods>
<operators>
<operator name="operator !=">
<return type="bool" />
<param index="0" name="right" type="Array" />
<description>
Returns [code]true[/code] if the array's size or its elements are different than [param right]'s.
</description>
</operator>
<operator name="operator +">
<return type="Array" />
<param index="0" name="right" type="Array" />
<description>
Appends the [param right] array to the left operand, creating a new [Array]. This is also known as an array concatenation.
[codeblocks]
[gdscript]
var array1 = ["One", 2]
var array2 = [3, "Four"]
print(array1 + array2) # Prints ["One", 2, 3, "Four"]
[/gdscript]
[csharp]
// Note that concatenation is not possible with C#'s native Array type.
var array1 = new Godot.Collections.Array{"One", 2};
var array2 = new Godot.Collections.Array{3, "Four"};
GD.Print(array1 + array2); // Prints ["One", 2, 3, "Four"]
[/csharp]
[/codeblocks]
[b]Note:[/b] For existing arrays, [method append_array] is much more efficient than concatenation and assignment with the [code]+=[/code] operator.
</description>
</operator>
<operator name="operator &lt;">
<return type="bool" />
<param index="0" name="right" type="Array" />
<description>
Compares the elements of both arrays in order, starting from index [code]0[/code] and ending on the last index in common between both arrays. For each pair of elements, returns [code]true[/code] if this array's element is less than [param right]'s, [code]false[/code] if this element is greater. Otherwise, continues to the next pair.
If all searched elements are equal, returns [code]true[/code] if this array's size is less than [param right]'s, otherwise returns [code]false[/code].
</description>
</operator>
<operator name="operator &lt;=">
<return type="bool" />
<param index="0" name="right" type="Array" />
<description>
Compares the elements of both arrays in order, starting from index [code]0[/code] and ending on the last index in common between both arrays. For each pair of elements, returns [code]true[/code] if this array's element is less than [param right]'s, [code]false[/code] if this element is greater. Otherwise, continues to the next pair.
If all searched elements are equal, returns [code]true[/code] if this array's size is less or equal to [param right]'s, otherwise returns [code]false[/code].
</description>
</operator>
<operator name="operator ==">
<return type="bool" />
<param index="0" name="right" type="Array" />
<description>
Compares the left operand [Array] against the [param right] [Array]. Returns [code]true[/code] if the sizes and contents of the arrays are equal, [code]false[/code] otherwise.
</description>
</operator>
<operator name="operator &gt;">
<return type="bool" />
<param index="0" name="right" type="Array" />
<description>
Compares the elements of both arrays in order, starting from index [code]0[/code] and ending on the last index in common between both arrays. For each pair of elements, returns [code]true[/code] if this array's element is greater than [param right]'s, [code]false[/code] if this element is less. Otherwise, continues to the next pair.
If all searched elements are equal, returns [code]true[/code] if this array's size is greater than [param right]'s, otherwise returns [code]false[/code].
</description>
</operator>
<operator name="operator &gt;=">
<return type="bool" />
<param index="0" name="right" type="Array" />
<description>
Compares the elements of both arrays in order, starting from index [code]0[/code] and ending on the last index in common between both arrays. For each pair of elements, returns [code]true[/code] if this array's element is greater than [param right]'s, [code]false[/code] if this element is less. Otherwise, continues to the next pair.
If all searched elements are equal, returns [code]true[/code] if this array's size is greater or equal to [param right]'s, otherwise returns [code]false[/code].
</description>
</operator>
<operator name="operator []">
<return type="Variant" />
<param index="0" name="index" type="int" />
<description>
Returns the [Variant] element at the specified [param index]. Arrays start at index 0. If [param index] is greater or equal to [code]0[/code], the element is fetched starting from the beginning of the array. If [param index] is a negative value, the element is fetched starting from the end. Accessing an array out-of-bounds will cause a run-time error, pausing the project execution if run from the editor.
</description>
</operator>
</operators>
</class>