3.2. Maps

Data structures and algorithm > ch.3 sets and maps > 3.2. maps

 

A map is a container for storing a collection of data records in which each record is associated with a unique key.

The key components must be comparable

 

Map() 
# Creates a new empty map

length()
# returns the number of key/vlaue pairs in the map

contains(key)
# determines if the given key is in the map and returns True if the key is found and False otherwise

add(key, value)
# adds a new key/value pair to the map if the key is not already in themap or replaces the data associated with the key if the key is in the map
# returns True if this is a new key and False if the data associated with the existing key is replaced

remove(key)
# removes the key/value pair for the given key if iti s in the map and raises an exception otherwise

valueOf(key)
# returns the data record associated with the given key
# the key must exist in the map or an exception is raised

iterator()
# reates and returns an iterator that can be used to iterate over the keys in the map