Introducing the Map.entry interface

The map is an interface in Java, and Map.entry is an internal interface to the map. The Java.util.Map.Entry interface is mostly used when traversing a Map .

Map provides some common methods, such as KeySet (), EntrySet (), and so on , the KeySet () method return value is a collection of key values in map, and the return value of EntrySet () returns a set collection of type Map.entry.

Map.entry is an internal interface to the map declaration, which is generic and defined as entry<k,v>. It represents an entity (a Key-value pair) in a map. The interface has a getkey (), GetValue method.

 Packagetest;ImportJava.util.*;ImportJava.util.Map.Entry; Public classB { Public Static voidMain (string[] args) {Map<Integer,Integer> mm =NewHashmap<integer,integer>();  for(inti=0;i<10;i++) {Mm.put (I, I); }            for(Entry<integer, integer>E:mm.entryset ()) {System.out.println ("Key:" +E.getkey ()); System.out.println ("Value:" +E.getvalue ()); }            for(Iterator<entry<integer, integer>> i =Mm.entryset (). iterator (); I.hasnext ();) {Entry<integer, integer> e =I.next (); System.out.println ("Key:" +E.getkey ()); System.out.println ("Value:" +E.getvalue ()); }        }   49}

Introducing the Map.entry interface