Created: 2023-09-03 20:46
Status: #concept
Subject: Programming
Tags: Java java.util java.util.HashMap Java Interface

java.util.Map

It is a mapping of keys to values.

The Map interface provides three collection views, which allow a map's contents to be viewed as a .keySet(), collection of .values(), or set of key-value mappings which we can .put(key, value) or .get(key).

All Known Implementing Classes:

AbstractMap, Attributes, AuthProvider, ConcurrentHashMap, ConcurrentSkipListMap, EnumMap, HashMap, Hashtable, IdentityHashMap, LinkedHashMap, PrinterStateReasons, Properties, Provider, RenderingHints, SimpleBindings, TabularDataSupport, TreeMap, UIDefaults, WeakHashMap

Map<String, String> maps = new HashMap<>();
maps.put("ganbatte", "good luck");
maps.put("hai", "yes");

for (String key : maps.keySet()) {
    System.out.println(key + ": " + maps.get(key));
}

// ganbatte: good luck
// hai: yes

References