AbstractMap.SimpleEntry hashCode() Method in Java with Examples
AbstractMap.SimpleEntry<K, V> is used to maintain a key and a value entry. The value can be changed using the setValue method. This class facilitates the process of building custom map implementations.
hashCode() method of AbstractMap.SimpleEntry<K, V> return the hash code value for this map entry.
The hash code for the map entry e can be calculated by:
(e.getKey()==null ? 0 : e.getKey().hashCode()) ^ (e.getValue()==null ? 0 : e.getValue().hashCode())
Syntax:
public int hashCode()
Parameters: This method accepts nothing.
Return value: This method return the hash code value for this map entry.
Below programs illustrate hashCode() method:
Program 1:
// Java program to demonstrate// AbstractMap.SimpleEntry.hashCode() method import java.util.*;import java.util.AbstractMap.SimpleEntry; public class GFG { @SuppressWarnings({ "unchecked", "rawtypes" }) public static void main(String[] args) { // create a ArrayList of Map ArrayList<AbstractMap .SimpleEntry<Integer, Integer> > arrayList = new ArrayList<AbstractMap .SimpleEntry<Integer, Integer> >(); // add values arrayList.add(new AbstractMap.SimpleEntry(0, 123)); arrayList.add(new AbstractMap.SimpleEntry(1, 130)); arrayList.add(new AbstractMap.SimpleEntry(2, 994)); // print keys for (int i = 0; i < arrayList.size(); i++) { // get map from list AbstractMap.SimpleEntry<Integer, Integer> map = arrayList.get(i); // get value from map using hashCode() int value = map.hashCode(); System.out.println("HashCode = " + value); } }} |
Output:
HashCode = 123 HashCode = 131 HashCode = 992
Program 2:
// Java program to demonstrate// AbstractMap.SimpleEntry.hashCode() method import java.util.*; public class GFG { @SuppressWarnings({ "unchecked", "rawtypes" }) public static void main(String[] args) { // create a ArrayList of Map ArrayList<AbstractMap .SimpleEntry<String, String> > arrayList = new ArrayList<AbstractMap .SimpleEntry<String, String> >(); // add values arrayList.add(new AbstractMap .SimpleEntry(" 001AB ", " Emp 1")); arrayList.add(new AbstractMap .SimpleEntry(" 011AC ", " Emp 2")); arrayList.add(new AbstractMap .SimpleEntry(" 111AD ", " Emp 3")); arrayList.add(new AbstractMap .SimpleEntry(" 101BE ", " Emp 4")); arrayList.add(new AbstractMap .SimpleEntry(" 110CE ", " Emp 5")); // print keys for (int i = 0; i < arrayList.size(); i++) { // get map from list AbstractMap.SimpleEntry<String, String> map = arrayList.get(i); // get hashcode value from map using hashCode() int value = map.hashCode(); System.out.println("hashCode = " + value); } }} |
Output:
hashCode = -873386249 hashCode = -874293612 hashCode = -910934441 hashCode = -910552137 hashCode = -910906733
References: https://docs.oracle.com/javase/10/docs/api/java/util/AbstractMap.SimpleEntry.html#hashCode()
