java/w8/Pair.java

package Homework;

public class Pair<K,V> {
    private K key;
    private V value;
    
    public Pair(K key,V value){
        this.key=key;
        this.value=value;
    }
    
    public K getKey(){
        return key;
    }
    
    public V getValue(){
        return value;
    }
    
    public void setKey(K key){
        this.key=key;
    }
    
    public void setValue(V value){
        this.value=value;
    }

    public static <K,V> Pair<V,K> swap(Pair<K,V>pair){
        return new Pair<>(pair.getValue(),pair.getKey());
    }

    public static void main(String[] args) {
        Pair<String,Integer> p=new Pair<>("hello",10);
        System.out.println(p.getKey());
        System.out.println(p.getValue());
        p.setKey("world");
        p.setValue(20);
        System.out.println(p.getKey());
        System.out.println(p.getValue());
    }
}