import java.util.ArrayList;import java.util.HashMap;import java.util.HashSet;import java.util.List;import java.util.Map;import java.util.Set;public class MapTest {	public static void main(String[] args) {		Map m =new HashMap();		m.put("1", 2);		Object i  = m.get("1");		System.out.println(m.put("1", 3));		System.out.println(m.get("1"));				Set set = new HashSet();		set.add("5");		System.out.println(set.add("5"));				List li = new ArrayList();		set.add("6");		System.out.println(set.add("6"));				System.out.println("----Map------------------------");		m.put(new T("A"), "d");		m.put(new T("A"), "f");		m.put(new T("A"), "g");				System.out.println("----set------------------------");		set.add(new T("A"));		set.add(new T("A"));		set.add(new T("A"));				System.out.println("----list------------------------");				li.add(new T("A"));		li.add(new T("A"));		li.add(new T("A"));	}}class T{	private String hashcode;	public T(String hsCode){		hashcode = hsCode;	}		@Override	public int hashCode() {		// TODO Auto-generated method stub		System.out.println("hashcode Function ");		return hashcode.hashCode();	}		@Override	public boolean equals(Object obj) {		System.out.println("equals Function ");		// TODO Auto-generated method stub		return super.equals(obj);	}}

23falsefalse----Map------------------------hashcode Function hashcode Function equals Function hashcode Function equals Function equals Function ----set------------------------hashcode Function hashcode Function equals Function hashcode Function equals Function equals Function ----list------------------------