List,Map,Set add方法
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;}@Overridepublic int hashCode() {// TODO Auto-generated method stubSystem.out.println("hashcode Function ");return hashcode.hashCode();}@Overridepublic boolean equals(Object obj) {System.out.println("equals Function ");// TODO Auto-generated method stubreturn 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------------------------
?