1,ArrayList的Generics

public class ArrayListGenericDemo
{

public static void main(String[] args)
{
ArrayList<String> data = new ArrayList<String>();
data.add("hello");
data.add("goodbye");
// data.add(new Date()); This won't compile!
Iterator<String> it = data.iterator();

while (it.hasNext())
{
String s = it.next();
System.out.println(s);
}
}
}
2,HashMap的Generics

public class ArrayListGenericDemo
{

public static void main(String[] args)
{
ArrayList<String> data = new ArrayList<String>();
data.add("hello");
data.add("goodbye");
// data.add(new Date()); This won't compile!
Iterator<String> it = data.iterator();

while (it.hasNext())
{
String s = it.next();
System.out.println(s);
}
}
}





































