Example 1: Program to print half pyramid using *

*
* *
* * *
* * * *
* * * * *

Source code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 5;
6. for(int i = 1; i <= rows; ++i) {
7. for(int j = 1; j <= i; ++j) {
8. System.out.print("* ");
9. }
10. System.out.println();
11. }
12. }
13. }

Example 2: Program to print half pyramid a using numbers

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 5;
6. for(int i = 1; i <= rows; ++i) {
7. for(int j = 1; j <= i; ++j) {
8. System.out.print(j + " ");
9. }
10. System.out.println();
11. }
12. }
13. }

Example 3: Program to print half pyramid using alphabets

A
B B
C C C
D D D D
E E E E E

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. char last = 'E', alphabet = 'A';
6. for(int i = 1; i <= (last-'A'+1); ++i) {
7. for(int j = 1; j <= i; ++j) {
8. System.out.print(alphabet + " ");
9. }
10. ++alphabet;
12. System.out.println();
13. }
14. }
15. }

Programs to print inverted half pyramid using * and numbers

Example 4: Inverted half pyramid using *

* * * * *
* * * *
* * * 
* *
*

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 5;
6. for(int i = rows; i >= 1; --i) {
7. for(int j = 1; j <= i; ++j) {
8. System.out.print("* ");
9. }
10. System.out.println();
11. }
12. }
13. }

Example 5: Inverted half pyramid using numbers

1 2 3 4 5
1 2 3 4 
1 2 3
1 2
1

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 5;
6. for(int i = rows; i >= 1; --i) {
7. for(int j = 1; j <= i; ++j) {
8. System.out.print(j + " ");
9. }
10. System.out.println();
11. }
12. }
13. }

 Programs to display pyramid and inverted pyramid using * and digits

Example 6: Program to print full pyramid using *

        *
      * * *
    * * * * *
  * * * * * * *
* * * * * * * * *

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 5, k = 0;
6. for(int i = 1; i <= rows; ++i, k = 0) {
7. for(int space = 1; space <= rows - i; ++space) {
8. System.out.print(" ");
9. }
11. while(k != 2 * i - 1) {
12. System.out.print("* ");
13. ++k;
14. }
16. System.out.println();
17. }
18. }
19. }

Example 7: Program to print pyramid using numbers

        1
      2 3 2
    3 4 5 4 3
  4 5 6 7 6 5 4
5 6 7 8 9 8 7 6 5

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 5, k = 0, count = 0, count1 = 0;
6. for(int i = 1; i <= rows; ++i) {
7. for(int space = 1; space <= rows - i; ++space) {
8. System.out.print(" ");
9. ++count;
10. }
12. while(k != 2 * i - 1) {
13. if (count <= rows - 1) {
14. System.out.print((i + k) + " ");
15. ++count;
16. }
17. else {
18. ++count1;
19. System.out.print((i + k - 2 * count1) + " ");
20. }
22. ++k;
23. }
24. count1 = count = k = 0;
26. System.out.println();
27. }
28. }
29. }

Example 8: Inverted full pyramid using *

* * * * * * * * *
  * * * * * * *
    * * * * *
      * * *
        *

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 5;
6. for(int i = rows; i >= 1; --i) {
7. for(int space = 1; space <= rows - i; ++space) {
8. System.out.print(" ");
9. }
11. for(int j=i; j <= 2 * i - 1; ++j) {
12. System.out.print("* ");
13. }
15. for(int j = 0; j < i - 1; ++j) {
16. System.out.print("* ");
17. }
19. System.out.println();
20. }
21. }
22. }

Example 9: Print Pascal’s triangle

           1
         1   1
       1   2   1
     1   3   3    1
   1   4   6   4   1
 1   5   10   10  5   1

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 6, coef = 1;
6. for(int i = 0; i < rows; i++) {
7. for(int space = 1; space < rows - i; ++space) {
8. System.out.print(" ");
9. }
11. for(int j = 0; j <= i; j++) {
12. if (j == 0 || i == 0)
13. coef = 1;
14. else
15. coef = coef * (i - j + 1) / j;
17. System.out.printf("%4d", coef);
18. }
20. System.out.println();
21. }
22. }
23. }

Example 10: Print Floyd’s Triangle.

1
2 3
4 5 6
7 8 9 10

Source Code

1. public class Pattern {
3. public static void main(String[] args) {
4. int rows = 4, number = 1;
6. for(int i = 1; i <= rows; i++) {
8. for(int j = 1; j <= i; j++) {
9. System.out.print(number + " ");
10. ++number;
11. }
13. System.out.println();
14. }
15. }
16. }