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,
}
var myDict = new Godot.Collections.Dictionary(); // Creates an empty dictionary.
var pointsDict = new Godot.Collections.Dictionary
{
{"White", 50},
{"Yellow", 75},
{"Orange", 100}
};
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]
[Export(PropertyHint.Enum, "White,Yellow,Orange")]
public string MyColor { get; set; }
private Godot.Collections.Dictionary _pointsDict = new Godot.Collections.Dictionary
{
{"White", 50},
{"Yellow", 75},
{"Orange", 100}
};
public override void _Ready()
{
int points = (int)_pointsDict[MyColor];
}
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.
}
var myDict = new Godot.Collections.Dictionary
{
{"First Array", new Godot.Collections.Array{1, 2, 3, 4}}
};
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.
var pointsDict = new Godot.Collections.Dictionary
{
{"White", 50},
{"Yellow", 75},
{"Orange", 100}
};
pointsDict["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"},
}
// This is a valid dictionary.
// To access the string "Nested value" below, use `((Godot.Collections.Dictionary)myDict["sub_dict"])["sub_key"]`.
var myDict = new Godot.Collections.Dictionary {
{"String Key", 5},
{4, new Godot.Collections.Array{1,2,3}},
{7, "Hello"},
{"sub_dict", new Godot.Collections.Dictionary{{"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]
var groceries = new Godot.Collections.Dictionary{{"Orange", 20}, {"Apple", 2}, {"Banana", 4}};
foreach (var (fruit, amount) in groceries)
{
// `fruit` is the key, `amount` is the value.
}
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.
Note
There are notable differences when using this API with C#. See C# API differences to GDScript for more information.
Tutorials¶
Constructors¶
Dictionary ( ) |
|
Dictionary ( Dictionary from ) |
Methods¶
void |
clear ( ) |
hash ( ) const |
|
is_empty ( ) const |
|
is_read_only ( ) const |
|
keys ( ) const |
|
void |
make_read_only ( ) |
void |
merge ( Dictionary dictionary, bool overwrite=false ) |
size ( ) const |
|
values ( ) const |
Operators¶
operator != ( Dictionary right ) |
|
operator == ( Dictionary right ) |
|
operator [] ( Variant key ) |
Constructor Descriptions¶
Dictionary Dictionary ( )
Constructs an empty Dictionary.
Dictionary Dictionary ( Dictionary from )
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 ( bool deep=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 ( Variant value ) 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 ( Variant key, Variant default=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.
bool has ( Variant key ) 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
var myDict = new Godot.Collections.Dictionary
{
{ "Godot", 4 },
{ 210, default },
};
GD.Print(myDict.ContainsKey("Godot")); // Prints true
GD.Print(myDict.ContainsKey(210)); // Prints true
GD.Print(myDict.ContainsKey(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 ( Array keys ) 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
int hash ( ) const
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
var dict1 = new Godot.Collections.Dictionary{{"A", 10}, {"B", 2}};
var dict2 = new Godot.Collections.Dictionary{{"A", 10}, {"B", 2}};
// Godot.Collections.Dictionary has no Hash() method. Use GD.Hash() instead.
GD.Print(GD.Hash(dict1) == GD.Hash(dict2)); // 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.
bool is_empty ( ) const
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.
Array keys ( ) const
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, bool overwrite=false )
Adds entries from dictionary
to this dictionary. By default, duplicate keys are not copied over, unless overwrite
is true
.
int size ( ) const
Returns the number of entries in the dictionary. Empty dictionaries ({ }
) always return 0
. See also is_empty.
Array values ( ) const
Returns the list of values in this dictionary.
Operator Descriptions¶
bool operator != ( Dictionary right )
Returns true
if the two dictionaries do not contain the same keys and values.
bool operator == ( Dictionary right )
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 [] ( Variant key )
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.