Map

A map container backed by either a hash map or a linked hash map.

Map type

map<KeyType, ValueType>

Subtypes	Supertypes	Comparable types
sorted_map<KeyType, ValueType>	sequence< mapping<KeyType, ValueType> >	java.util.Map<KeyType, ValueType>

The map type is retrofitted to be a subtype of sequence.

Map creation

new hashmap
new linked_hashmap

Parameter type	Result type
(KeyType => ValueType)...	map<KeyType, ValueType>

Creates an empty map. Optionally, initial values may be specified right in the new map creation expression.

map<string, int> map = new hashmap<string, int> {"A" = 1, "B" = 2, "C" = 3};

Operations on map

get value by key

Operand type	Parameter type	Result type
map<KeyType, ValueType>	KeyType	ValueType

int value = map["key"];

keys

Operand type	Parameter type	Result type
map<KeyType, ValueType>	none	sequence<KeyType>

Results in a sequence containing all the keys in the map.

sequence<string> keys = map.keys;

containsKey

Operand type	Parameter type	Result type
map<KeyType, ValueType>	KeyType	boolean

Returns true if the map contains a mapping for the specified key, false otherwise.

map.containsKey ("key");

values

Operand type	Parameter type	Result type
map<KeyType, ValueType>	none	sequence<ValueType>

Results in a sequence containing all the values in the map.

sequence<string> values = map.values;

containsValue

Operand type	Parameter type	Result type
map<KeyType, ValueType>	ValueType	boolean

Returns true if the map contains a mapping with the specified value, false otherwise.

map.containsValue ("value");

mappings

Operand type	Parameter type	Result type
map<KeyType, ValueType>	none	set< mapping<KeyType, ValueType> >

Results in a set of mappings contained by this map. The mappings can be removed from the set, but not added.

set<mappings<K,V>> = map.mappings;

assign value to a key

Operand type	Parameter type	Result type
map<KeyType, ValueType>	KeyType	ValueType

map["key"] = value;

remove

Operand type	Parameter type	Result type
map<KeyType, ValueType>	KeyType	void

Removes the specified key and the associated value from the map.

map.remove ("key");

clear

Operand type	Parameter type	Result type
map<KeyType, ValueType>	none	void

Clears all key-value pairs from the map.

map.clear;

putAll

Operand type	Parameter type	Result type
map<KeyType, ValueType>	map<KeyType, ValueType>	void

Puts all mappings from the map specified as a parameter into this map, replacing existing mappings.

map.putAll (anotherMap);

Last modified: 5 July 2019