java运行出来显示菱形问号怎么办 java实现菱形输出

1. import java.util.Scanner;
2. public class dengyao2 {
3. public dengyao2() {
4. super();
5. }
6. public static void main(String[] args) {
7. System.out.println("请输入菱形的边长：");
8. Scanner input = new Scanner(System.in);
9. if (input.hasNextInt()) {
10. int a = input.nextInt();
11. dengyao2 triangle = new dengyao2();
12. triangle.function(a);
13. } else {
14. System.out.println("你输入的格式有误！请输入整数！！");
15. }
16. input.close();
17. }
18. public void function(int x) {
19. for (int i = 1; i <= x; i++) {
20. for (int j = 1; j <= x - i; j++) {
21. System.out.print(" ");
22. }
23. for (int k = 1; k <= 2 * i - 1; k++) {
24. System.out.print("*");
25. }
26. System.out.println();
27. }
28. for (int i = x - 1; i > 0; i--) {
29. for (int j = 1; j <= x - i; j++) {
30. System.out.print(" ");
31. }
32. for (int k = 1; k <= 2 * i - 1; k++) {
33. System.out.print("*");
34. }
35. System.out.println();
36. }
37. }
38. }