import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
public class MainClass {
public static void main(String[] a) {
String elements[] = { "A", "B", "C", "D", "E" };
Set set = new HashSet(Arrays.asList(elements));
System.out.println(set.size());
}
}
Checking for no elements in the set: use the isEmpty() method instead
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;
/* w ww . ja va2 s . c om*/
public class MainClass {
public static void main(String[] a) {
String elements[] = { "A", "B", "C", "D", "E" };
Set set = new HashSet(Arrays.asList(elements));
System.out.println(set.isEmpty());
}
}
运行结果如下:
【set】
