public class Pair { private final Object first; private final Object second; public Pair(Object first,Object second) { this.first=first; this.second=second; } public Object getFirst() { return first; } public Object getSecond() { return second; } public static void main(String[] args) { Pair p1=new Pair("toto","titi"); Pair p2=new Pair(2,p1); Pair p3=(Pair)p2.getSecond(); } }
Qu'affiche le code ci-dessous ?
Map<Pair<String,String>,String> map=new HashMap<Pair<String,String>,String>(); map.put(new Pair<String,String>("jean-paul","sartre"),"mort"); map.put(new Pair<String,String>("elvis","presley"),"vivant"); map.remove(new Pair<String,String>("elvis","presley")); System.out.println(map);Que doit-on faire pour résoudre le problème ?
public static void main(String[] args) { ArrayList<String> l1=new ArrayList<String>(); ArrayList<Object> l2=l1; }
public static void main(String[] args) { ArrayList<String> l1=new ArrayList<String>(); ArrayList<Object> l2=l1; for(Object o:l2) System.out.println(o); }
public static void main(String[] args) { Pair p1=new Pair("toto","titi"); Pair p2=new Pair(2,p1); Pair p4; if (args.length%2==0) p4=p1; else p4=p2; Comparable c=(Comparable)p4.getFirst(); }
public static void main(String[] args) { List<String> l1=Arrays.asList(args); List<String> l2=new ArrayList<String>(); copy(l2,l1); }
public static void main(String[] args) { List<Integer> l1=Arrays.asList(2,3); List<Number> l2=new ArrayList<Number>(); copy(l2,l1); }
public static void main(String[] args) { List<String> l1=Arrays.asList(args); fill(l1,"toto"); }
java Unique toto tutu toto titi tutu