Dictionary ​
A built-in data structure that holds key-value pairs.
Description
Dictionaries are associative containers that contain values referenced by unique keys. Dictionaries will preserve the insertion order when adding new entries. In other programming languages, this data structure is often referred to as a hash map or an associative array.
You can define a dictionary by placing a comma-separated list of key: value
pairs inside curly braces {}
.
Creating a dictionary:
var my_dict = {} # Creates an empty dictionary.
var dict_variable_key = "Another key name"
var dict_variable_value = "value2"
var another_dict = {
"Some key name": "value1",
dict_variable_key: dict_variable_value,
}
var points_dict = {"White": 50, "Yellow": 75, "Orange": 100}
# Alternative Lua-style syntax.
# Doesn't require quotes around keys, but only string constants can be used as key names.
# Additionally, key names must start with a letter or an underscore.
# Here, `some_key` is a string literal, not a variable!
another_dict = {
some_key = 42,
}
You can access a dictionary's value by referencing its corresponding key. In the above example, points_dict["White"]
will return 50
. You can also write points_dict.White
, which is equivalent. However, you'll have to use the bracket syntax if the key you're accessing the dictionary with isn't a fixed string (such as a number or variable).
@export_enum("White", "Yellow", "Orange") var my_color: String
var points_dict = {"White": 50, "Yellow": 75, "Orange": 100}
func _ready():
# We can't use dot syntax here as `my_color` is a variable.
var points = points_dict[my_color]
In the above code, points
will be assigned the value that is paired with the appropriate color selected in my_color
.
Dictionaries can contain more complex data:
var my_dict = {
"First Array": [1, 2, 3, 4] # Assigns an Array to a String key.
}
To add a key to an existing dictionary, access it like an existing key and assign to it:
var points_dict = {"White": 50, "Yellow": 75, "Orange": 100}
points_dict["Blue"] = 150 # Add "Blue" as a key and assign 150 as its value.
Finally, dictionaries can contain different types of keys and values in the same dictionary:
# This is a valid dictionary.
# To access the string "Nested value" below, use `my_dict.sub_dict.sub_key` or `my_dict["sub_dict"]["sub_key"]`.
# Indexing styles can be mixed and matched depending on your needs.
var my_dict = {
"String Key": 5,
4: [1, 2, 3],
7: "Hello",
"sub_dict": {"sub_key": "Nested value"},
}
The keys of a dictionary can be iterated with the for
keyword:
var groceries = {"Orange": 20, "Apple": 2, "Banana": 4}
for fruit in groceries:
var amount = groceries[fruit]
Note: Dictionaries are always passed by reference. To get a copy of a dictionary which can be modified independently of the original dictionary, use duplicate.
Note: Erasing elements while iterating over dictionaries is not supported and will result in unpredictable behavior.
INFO
There are notable differences when using this API with C#. See C# API differences to GDScript for more information.
Tutorials
Constructors
Dictionary(from: Dictionary) |
Methods
void | clear() |
get_or_add(key: Variant, default: Variant = null) | |
hash() const | |
is_empty() const | |
is_read_only() const | |
keys() const | |
void | |
void | merge(dictionary: Dictionary, overwrite: bool = false) |
merged(dictionary: Dictionary, overwrite: bool = false) const | |
recursive_equal(dictionary: Dictionary, recursion_count: int) const | |
size() const | |
values() const |
Operators
operator !=(right: Dictionary) | |
operator ==(right: Dictionary) | |
operator [](key: Variant) |
Constructor Descriptions
Dictionary Dictionary() 🔗
Constructs an empty Dictionary.
Dictionary Dictionary(from: Dictionary)
Returns the same dictionary as from
. If you need a copy of the dictionary, use duplicate.
Method Descriptions
void clear() 🔗
Clears the dictionary, removing all entries from it.
Dictionary duplicate(deep: bool = false) const 🔗
Creates and returns a new copy of the dictionary. If deep
is true
, inner Dictionary and Array keys and values are also copied, recursively.
Removes the dictionary entry by key, if it exists. Returns true
if the given key
existed in the dictionary, otherwise false
.
Note: Do not erase entries while iterating over the dictionary. You can iterate over the keys array instead.
Variant find_key(value: Variant) const 🔗
Finds and returns the first key whose associated value is equal to value
, or null
if it is not found.
Note: null
is also a valid key. If inside the dictionary, find_key may give misleading results.
Variant get(key: Variant, default: Variant = null) const 🔗
Returns the corresponding value for the given key
in the dictionary. If the key
does not exist, returns default
, or null
if the parameter is omitted.
Variant get_or_add(key: Variant, default: Variant = null) 🔗
Gets a value and ensures the key is set. If the key
exists in the dictionary, this behaves like get. Otherwise, the default
value is inserted into the dictionary and returned.
bool has(key: Variant) const 🔗
Returns true
if the dictionary contains an entry with the given key
.
var my_dict = {
"Godot" : 4,
210 : null,
}
print(my_dict.has("Godot")) # Prints true
print(my_dict.has(210)) # Prints true
print(my_dict.has(4)) # Prints false
In GDScript, this is equivalent to the in
operator:
if "Godot" in {"Godot": 4}:
print("The key is here!") # Will be printed.
Note: This method returns true
as long as the key
exists, even if its corresponding value is null
.
bool has_all(keys: Array) const 🔗
Returns true
if the dictionary contains all keys in the given keys
array.
var data = {"width" : 10, "height" : 20}
data.has_all(["height", "width"]) # Returns true
Returns a hashed 32-bit integer value representing the dictionary contents.
var dict1 = {"A": 10, "B": 2}
var dict2 = {"A": 10, "B": 2}
print(dict1.hash() == dict2.hash()) # Prints true
Note: Dictionaries with the same entries but in a different order will not have the same hash.
Note: Dictionaries with equal hash values are not guaranteed to be the same, because of hash collisions. On the contrary, dictionaries with different hash values are guaranteed to be different.
Returns true
if the dictionary is empty (its size is 0
). See also size.
bool is_read_only() const 🔗
Returns true
if the dictionary is read-only. See make_read_only. Dictionaries are automatically read-only if declared with const
keyword.
Returns the list of keys in the dictionary.
void make_read_only() 🔗
Makes the dictionary read-only, i.e. disables modification of the dictionary's contents. Does not apply to nested content, e.g. content of nested dictionaries.
void merge(dictionary: Dictionary, overwrite: bool = false) 🔗
Adds entries from dictionary
to this dictionary. By default, duplicate keys are not copied over, unless overwrite
is true
.
var dict = { "item": "sword", "quantity": 2 }
var other_dict = { "quantity": 15, "color": "silver" }
# Overwriting of existing keys is disabled by default.
dict.merge(other_dict)
print(dict) # { "item": "sword", "quantity": 2, "color": "silver" }
# With overwriting of existing keys enabled.
dict.merge(other_dict, true)
print(dict) # { "item": "sword", "quantity": 15, "color": "silver" }
Note: merge is not recursive. Nested dictionaries are considered as keys that can be overwritten or not depending on the value of overwrite
, but they will never be merged together.
Dictionary merged(dictionary: Dictionary, overwrite: bool = false) const 🔗
Returns a copy of this dictionary merged with the other dictionary
. By default, duplicate keys are not copied over, unless overwrite
is true
. See also merge.
This method is useful for quickly making dictionaries with default values:
var base = { "fruit": "apple", "vegetable": "potato" }
var extra = { "fruit": "orange", "dressing": "vinegar" }
# Prints { "fruit": "orange", "vegetable": "potato", "dressing": "vinegar" }
print(extra.merged(base))
# Prints { "fruit": "apple", "vegetable": "potato", "dressing": "vinegar" }
print(extra.merged(base, true))
bool recursive_equal(dictionary: Dictionary, recursion_count: int) const 🔗
Returns true
if the two dictionaries contain the same keys and values, inner Dictionary and Array keys and values are compared recursively.
Returns the number of entries in the dictionary. Empty dictionaries ({ }
) always return 0
. See also is_empty.
Returns the list of values in this dictionary.
Operator Descriptions
bool operator !=(right: Dictionary) 🔗
Returns true
if the two dictionaries do not contain the same keys and values.
bool operator ==(right: Dictionary) 🔗
Returns true
if the two dictionaries contain the same keys and values. The order of the entries does not matter.
Note: In C#, by convention, this operator compares by reference. If you need to compare by value, iterate over both dictionaries.
Variant operator [](key: Variant) 🔗
Returns the corresponding value for the given key
in the dictionary. If the entry does not exist, fails and returns null
. For safe access, use get or has.