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Arrays

Arrays are a collection of values/items stored together.

In GDScript, arrays can contain values of different data types.

var example = [] # an empty array
var anotherExample = [1, "hello", true] # an array with different data types

You are able to retrieve a single element from the array:

var example = [10, 20, 30]
var firstElement = example[0] # 10
var secondElement = example[1] # 20
var thirdElement = example[2] # 30

Length of an Array

To get the length of an array, use the size method:

var example = [ 1,2,3 ] 

var length = example.size()
print(length) # 3

Sub Arrays

You can have arrays inside of arrays. These are called sub-arrays.

var subArray = [ [1,2], [9,10] ] # an empty array

# Get a value from the first subarray
var subarrayValueOne = subArray[0][0] # 1
var subarrayValueTwo = subArray[1][1] # 10

Push and Pop Methods

To push a value to either the front or back of an array, use the push method:

var example = [ 1,2,3 ] # an empty array

# Get a value from the first subarray
example.push_front(0) # example = [0,1,2,3]
example.push_back(4) # example = [0,1,2,3,4]

To pop a value out of an array, you can use the pop method:

var example = [ 1,2,3 ] # an empty array

# Get a value from the first subarray
example.pop_front() # example = [2,3]
example.pop_back() # example = [3]

Empty an array

There are a few ways to clear an array:

You can assign an empty array

var example = [ 1,2,3 ]

example = []

You can resize an array using the resize method

var example = [ 1,2,3 ] 

example.resize(0)

You can clear an array using the clear method

var example = [ 1,2,3 ] 

example.clear()

Duplicate an array

In Godot, if you try to pass an array to another variable, an issue occurs.

The issue is that two variables will have access to the same array values.

var example = [ 1,2,3 ] 

var anotherArray = example # anotherArray = [1,2,3]

anotherArray.push_front(4)

print(example) # [1,2,3,4]

To avoid this issue, you will need to implement either a deep copy or a shallow copy.

Shallow Copy

A shallow copy copies the array except for sub-arrays.

This means that all nested arrays and dictionaries will be shared with the original array.

A shallow copy uses the duplicate method with the false value passed inside the parentheses.

var example = [ 1,2,3, [1,2] ] 

var anotherArray = example.duplicate(false) # anotherArray = [1,2,3,[1,2]]

anotherArray.push_front(4)

print(example) # [1,2,3,[1,2]]

anotherArray[3][0] = 100

print(example) # [1,2,3,[100,2]]
print(anotherArray) # [1,2,3,[100,2],4]

Deep Copy

A deep copy copies the array, including sub-arrays.

This means that all nested arrays and dictionaries will not be shared with the original array.

To do a deep copy, use the duplicate method with the value true passed inside the parentheses.

var example = [ 1,2,3, [1,2] ] 

var anotherArray = example.duplicate(true) # anotherArray = [1,2,3,[1,2]]

anotherArray.push_front(4)

print(example) # [1,2,3,[1,2]]

anotherArray[3][0] = 100

print(example) # [1,2,3,[1,2]]
print(anotherArray) # [1,2,3,[100,2],4]