public class Main {
public static void main(String [] args) {
System.out.println( "集合实例!\n" );
int size;
HashSet collection = new HashSet ();
String str1 = "Yellow", str2 = "White", str3 =
"Green", str4 = "Blue";
Iterator iterator;
collection.add(str1);
collection.add(str2);
collection.add(str3);
collection.add(str4);
System.out.print("集合数据: ");
iterator = collection.iterator();
while (iterator.hasNext()){
System.out.print(iterator.next() + " ");
}
System.out.println();
size = collection.size();
if (collection.isEmpty()){
System.out.println("集合是空的");
}
else{
System.out.println( "集合长度: " + size);
}
System.out.println();
}
}