Intro

A hash table, also known as hash map is a data structure that can map keys to values. It should be used instead of the hashtable type if you don’t require two keys. Unlike the Jass hashtable which exposes a wide amount of functions to load, save and remove values, the class HashMap<K, V> is generic with K being the type of the key and V being the type of the value you want to save.

Basic Usage

Due to its generic nature, the calls on the hashmap will be the same regardless of the types used.

class A

class B

@Test function testMap()
	let map = new HashMap<A, B>
	let a = new A()
	let b = new B()
	// Add a value for the key. Existing values will be overriden
	map.put(a, b)
	// Check if the map contains a value associated with the key
	map.has(a).assertTrue()
	// Get a value
	let a2 = map.get(a)
	// Remove the entry
	map.remove(a)
	map.has(a).assertFalse()

Other Examples

Using the TypeCasting package, which is imported by default, we can also use jass types for K and V. For example attaching classes to units by using unit as key type and your class as value type.

class SomeDataClass

let dataMap = new HashMap<unit, SomeDataClass>

Iterable Map

Since a normal HashMap does not know it’s entries, you cannot iterate over them. For this case there is IterableMap which extends HashMap and combines it with a HashList storing the keys. Via those keys you can then access your values.

let iterMap = new IterableMap<int, int>
iterMap.put(0, 3)
iterMap.put(1, 2)
iterMap.put(2, 1)
iterMap.put(3, 0)

for key in iterMap
	let val = iterMap.get(key)
	Log.info("key: " +  key.toString() + " val: " + val.toString())