Map

To ground many of the ideas in the classification module, we introduce one of the most comprehensive data structures used in computer science, as well as numerous disciplines.

A Map is "an object that maps keys to values. A map cannot contain duplicate keys; each key can map to at most one value."

Numerous examples of maps exist in the real world:

• A telephone book maps names to phone numbers.
• An atlas maps street names (i.e., "Maple Street") to locations on a geographic map ("E7")
• A domain name server maps a computer name to an IP address.
• The periodic table maps an element's abbreviation (i.e., "Na") to a data sheet in which lots of information about that element may be found (i.e., atomic weight).

Given a map, there are numerous operations that one would like to perform:

• Cardinality
  • int size()
  • boolean isEmpty()
     
• Find
  • boolean containsKey (Object key)
  • boolean containsValue (Object value)
  • Object get (Object key)
     
• Insert
  • Object put (Object key, Object value)
     
• Remove
  • Object remove (Object key)
  • void clear ()