BlitzMax/Modules/Data structures/Maps

A map contains a set of key/value pairs. The keys and values may be any object type. A Red-Black Tree is used as the data structure. For ordered collections of objects, see Linked lists. Functions CreateMap Function CreateMap:TMap() Description: Create a map Returns: A new map object ClearMap Function ClearMap( map:TMap ) Description: Clear a map Information: ClearMap removes all keys and values from map MapIsEmpty Function MapIsEmpty( map:TMap ) Description: Check if a map is empty Returns: True if map is empty, otherwise false MapInsert Function MapInsert( map:TMap,key:Object,value:Object ) Description: Insert a key/value pair into a map Information: If map already contained key, its value is overwritten with value. Example: ' mapinsert.bmx Local map:TMap = CreateMap() MapInsert(map, "Key 1", "Value 1") Print MapIsEmpty(map) ClearMap(map) Print MapIsEmpty(map) MapValueForKey Function MapValueForKey:Object( map:TMap,key:Object ) Description: Find a value given a key Returns: The value associated with key Information: If map does not contain key, a Null object is returned. Example: ' mapvalueforkey.bmx Local map:TMap = CreateMap() MapInsert(map, "Key 1", "Value 1") Print String(MapValueForKey(map, "Key 1")) MapContains Function MapContains( map:TMap,key:Object ) Description: Check if a map contains a key Returns: True if map contains key Example: 'mapcontains.bmx Local map:TMap = CreateMap() MapInsert(map, "Key 1", "Value 1") Print MapContains(map, "Key 1") Print MapContains(map, "Key 2") MapRemove Function MapRemove( map:TMap,key:Object ) Description: Remove a key/value pair from a map Comment: Unlike the Remove method for TMap, this function does not return whether the key/value pair was removed or not. Example: ' mapremove.bmx Local map:TMap = CreateMap() MapInsert(map, "Key 1", "Value 1") Print MapContains(map, "Key 1") MapRemove(map, "Key 1") Print MapContains(map, "Key 1") MapKeys Function MapKeys:TMapEnumerator( map:TMap ) Description: Get map keys Returns: An iterator object Information: The object returned by MapKeys can be used with EachIn to iterate through the keys in map. Example: ' mapkeys.bmx Local map:TMap = CreateMap() MapInsert(map, "Key 1", "Value 1") MapInsert(map, "Key 2", "Value 2") Local obj:Object For obj = EachIn MapKeys(map) Print(String(obj) + "," + String(MapValueForKey(map, obj))) Next MapValues Function MapValues:TMapEnumerator( map:TMap ) Description: Get map values Returns: An iterator object Information: The object returned by MapValues can be used with EachIn to iterate through the values in map. Example: ' mapvalues.bmx Local map:TMap = CreateMap() MapInsert(map, "Key 1", "Value 1") MapInsert(map, "Key 2", "Value 2") Local obj:Object For obj = EachIn MapValues(map) Print String(obj) Next CopyMap Function CopyMap:TMap( map:TMap ) Description: Copy a map Returns: A copy of map Example: ' copymap.bmx Local map:TMap = CreateMap() MapInsert(map, "Key 1", "Value 1") Local map2:TMap = CopyMap(map) Print String(MapValueForKey(map2, "Key 1"))