小练习45

interface Sortable {
void sort(int arr[]);
}

public class Demo {

public static void main(String[] args) {
    Sortable s = java.util.Arrays::sort;
    int arr[] = { 9, 4, 1, 5, 2, 6, 3 };
    s.sort(arr);
    for (int x : arr) {
        System.out.print(x + " ");
    }
}

}