Pattern Program In Java

In this tutorial, we will learn to create Pattern program in Java. We will see 30 different patterns in Java with explanation and source code.

1. Square pattern in Java

The square pattern in Java is the simplest pattern that you can start with.

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

This pattern makes a shape of a square or you can shape it in a rectangle.

Steps to create a square pattern in Java:

Define the size of the square (or you can take user input).
Create a nested loop where the external loop is the number of rows and the inner loop is the number of columns.
Print the star in each column and print a new line after each row.

public class squarePattern {
  public static void main(String[] args) {

    // size of the square
    int size = 5;
    // outer loop
    for (int i = 0; i < size; i++) {
      // inner loop
      for (int j = 0; j < size; j++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

2. Hollow Square pattern

The hollow square is the same as the above pattern but stars only at the borders. Which makes it a hollow square.

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

Steps to create a hollow square pattern in Java:

Set size of the square (or take user input).
Create a nested loop where the external loop executes the number of rows.
In the internal loop, print star in the first and last row and only at the first and last column.
Break the line after each row.

public class hollowSquare {
  public static void main(String[] args) {

    // size of the square
    int size = 5;
    // outer loop
    for (int i = 0; i < size; i++) {
      // inner loop
      for (int j = 0; j < size; j++) {
        // print only star in first and last row
        if (i == 0 || i == size - 1) {
          System.out.print("*");
        }
        else {
          // print star only at first and last position row
          if (j == 0 || j == size - 1) {
            System.out.print("*");
          }
          else {
            System.out.print(" ");
          }
        }
      }
      System.out.println();
    }
  }
}

Output:

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

3. Left triangle star pattern in Java

The left triangle star pattern is also quite a simple pattern. It has a shape of a triangle with its perpendicular line at the left side.

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

Steps to create a left triangle star pattern in Java:

Take the size of the triangle.
Create a nested loop and repeat the outer loop for times equal to the size of the triangle.
Repeat the inner loop for times equal to the index of the outer loop and print star (*).
Use println to break the line after each row.

public class leftTrianlge {
  public static void main(String[] args) {

    // size of the triangle
    int size = 5;
    // loop to print the pattern
    for (int i = 0; i < size; i++) {
      // print column
      for (int j = 0; j <= i; j++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

4. Right triangle pattern program in Java

The right triangle star pattern is also the same as the left triangle star pattern but it has a shape of a triangle with its perpendicular line at the right side.

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

This is a bit harder than the left triangle star pattern because you also have to deal with spaces in the pattern.

Steps to create a right triangle star pattern:

Repeat the external loop to print columns of the triangle.
Inside this loop use, 2 different loops first to print spaces and second to print stars.
At the end of each row, create a new line.

public class rightTrianlge {
  public static void main(String[] args) {

    // size of the triangle
    int size = 5;
    // loop to print the pattern
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 1; j < size - i; j++) {
        System.out.print(" ");
      }
      // print stars
      for (int k = 0; k <= i; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

5. Left Down Triangle

You can see Left down triangle below.

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***
**
*

Here are the steps to create a downward triangle pattern program in Java:

Take the size of your triangle.
Create an external loop to print rows of triangles.
Create an inner loop that print star for times equal to size minus the outer loop index.

public class leftDown {
  public static void main(String[] args) {

    // size of the triangle
    int size = 5;
    for (int i = 0; i < size; i++) {
      // print stars
      for (int j = 0; j < size - i; j++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

6. Right Down Triangle

You can see Right down triangle below.

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

Here is the complete code create downward triangle pattern program in Java:

public class rightDown {
  public static void main(String[] args) {

    // size of the triangle
    int size = 5;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // print stars
      for (int j = size; j > i; j--) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

7. Hollow triangle star pattern in Java

The hollow triangle star pattern is a simple triangle pattern with stars only at its boundary making it hollow.

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

Steps to create hollow triangle pattern program in Java:

Set a size for the triangle and create an outer loop to print rows.
Inside the inner loop, if the index of the inner loop is last then print star (*) at first and last index of the inner loop.
If it is the last row then print only star (*).
Change line after each row.

public class hollowTrianlge {
  public static void main(String[] args) {

    // size of the triangle
    int size = 5;
    for (int i = 1; i <= size; i++) {
      for (int j = 0; j < i; j++) {
        // not last row
        if (i != size) {
          if (j == 0 || j == i - 1) {
            System.out.print("*");
          } else {
            System.out.print(" ");
          }
        }
        // last row
        else {
          System.out.print("*");
        }
      }
      System.out.println();
    }
  }
}

Output:

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

8. Pyramid star pattern in Java

The most famous star pattern is the pyramid pattern.

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

Steps to create a pyramid Java pattern programs:

Take the size and create an external loop to print all rows.
Inside the outer loop, we have to create 2 inner loops. First for printing spaces and second for printing stars.
print number of spaces equal to size minus the outer loop index in the first inner loop.
Inside the second inner loop, print the number of stars equal to 2 times the outer loop index minus 1.
A the end of these 2 inner loops create a new line.

public class pyramid {
  // pyramid star pattern
  public static void main(String[] args) {

    int size = 5;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < size - i - 1; j++) {
        System.out.print(" ");
      }
      // print stars
      for (int k = 0; k < 2 * i + 1; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

9. Reverse pyramid star pattern in Java

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

The reverse pyramid star pattern is the same as the pyramid star pattern but rotated 180 degrees.

This also follows the same logic as the pyramid star pattern just a different loop order.

public class reversePyramid {
  public static void main(String[] args) {
    // size of the pyramid
    int size = 5;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // print stars
      for (int k = 0; k < 2 * (size - i) - 1; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

10. Hollow pyramid pattern program in Java

The hollow pyramid is a hollow pyramid with stars only at corners.

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

Here are the steps to create a Hollow pyramid pattern program in Java:

Set size of the hollow pyramid.
Inside the external loop, we have to create 2 inner loops. First for printing spaces and second for printing stars.
The first loop print a number of spaces equal to size minus the outer loop index.
The second inner loop will run for 2 times the outer loop index plus 1 and print star only at the first and last index of the row.
Keep changing line after each row.

public class hollowPyramid {
  public static void main(String[] args) {
    // size of the pyramid
    int size = 5;
    for (int  i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < size - i - 1; j++) {
        System.out.print(" ");
      }
      // print stars
      for (int k = 0; k < 2 * i + 1; k++) {
        if (i == 0 || i == size - 1) {
          System.out.print("*");
        }
        else {
          if (k == 0 || k == 2 * i) {
            System.out.print("*");
          }
          else {
            System.out.print(" ");
          }
        }
      }
      System.out.println();
    }
  }
}

Output:

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

11. Diamond star pattern in Java

You can see here the diamond star pattern. It is made up of the pyramid and the reverse pyramid pattern.

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

If you combine the code of pyramid and reverse pyramid in the right order, you will get the diamond star pattern.

Here is complete code to create diamond pattern program in Java:

public class diamond {
  public static void main(String[] args) {
    int size = 5;
    // upside pyramid
    for (int i = 1; i <= size; i++) {
      // printing spaces
      for (int j = size; j > i; j--) {
        System.out.print(" ");
      }
      // printing star
      for (int k = 0; k < i * 2 - 1; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
    // downside pyramid
    for (int i = 1; i <= size - 1; i++) {
      // printing spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // printing star
      for (int k = (size - i) * 2 - 1; k > 0; k--) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

12. Hollow diamond star pattern in Java

The hollow diamond star pattern is the same as the diamond star pattern but stars only at the boundary.

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

Here is complete code to create hollow diamond pattern program in Java:

public class hollowDiamond {
  public static void main(String[] args) {
    int size = 5;
    // upside pyramid
    for (int i = 1; i <= size; i++) {
      // printing spaces
      for (int j = size; j > i; j--) {
        System.out.print(" ");
      }
      // printing star
      for (int k = 0; k < i * 2 - 1; k++) {
        if (k == 0 || k == 2 * i - 2) {
          System.out.print("*");
        }
        else {
          System.out.print(" ");
        }
      }
      System.out.println();
    }
    // downside triangle
    for (int i = 1; i < size; i++) {
      // printing spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // printing star
      for (int k = (size - i) * 2 - 1; k >= 1; k--) {
        if (k == 1 || k == (size - i) * 2 - 1) {
          System.out.print("*");
        }
        else {
          System.out.print(" ");
        }
      }
      System.out.println();
    }
  }
}

Output:

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

13. Hourglass star pattern in Java

You can see below the hourglass pattern. It is a combination of reverse pyramid and pyramid pattern.

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

Here is complete code to create hourglass pattern program in Java:

public class hourGlass {
  public static void main(String[] args) {
    int size = 5;
    // reversed pyramid star pattern
    for (int i = 0; i < size; i++) {
      // printing spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // printing star
      for (int k = 0; k < (size - i) * 2 - 1; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
    // pyramid star pattern
    for (int i = 2; i <= size; i++) {
      // printing spaces
      for (int j = size; j > i; j--) {
        System.out.print(" ");
      }
      // printing star
      for (int k = 0; k < i * 2 - 1; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

14. Right pascal star pattern

The right pascal star pattern is easy to create with 2 sets of nested for loops.

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

You can see in the above pattern it is a combination of the right triangle star pattern and reversed triangle star pattern together. Here is the complete code for the right pascal pattern program in Java.

public class leftPascal {
  public static void main(String[] args) {
    // left pasal triangle
    int size = 5;

    for (int i = 1; i <= size; i++) {
      for (int j = 0; j < i; j++) {
        System.out.print("*");
      }
      System.out.println();
    }
    
    for (int i = 1; i <= size - 1; i++) {
      for (int j = 0; j < size - i; j++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

15. Left pascal star pattern

The left pascal star pattern is the mirror image of the right pascal star pattern and you have to work with spaces also in this.

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

Here is complete code to create left pascal pattern program in Java:

public class leftPascal {
  public static void main(String[] args) {
    // left pasal triangle
    int size = 5;

    for (int i = 1; i <= size; i++) {
      for (int j = 0; j < size - i; j++) {
        System.out.print(" ");
      }
      for (int k = 0; k < i; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
    for (int i = 1; i <= size - 1; i++) {
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      for (int k = 0; k < size - i; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

16. Heart pattern

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

Heart star pattern is quite complex pattern. Here is complete code to create heart pattern program in Java:

public class heart {
  public static void main(String[] args) {
    // heart star pattern
    int size = 6;

    for (int i = size / 2; i < size; i += 2) {
      // print first spaces
      for (int j = 1; j < size - i; j += 2) {
        System.out.print(" ");
      }
      // print first stars
      for (int j = 1; j < i + 1; j++) {
        System.out.print("*");
      }
      // print second spaces
      for (int j = 1; j < size - i + 1; j++) {
        System.out.print(" ");
      }
      // print second stars
      for (int j = 1; j < i + 1; j++) {
        System.out.print("*");
      }
      System.out.println();
    }
    // lower part
    // inverted pyramid
    for (int i = size; i > 0; i--) {
      for (int j = 0; j < size - i; j++) {
        System.out.print(" ");
      }
      for (int j = 1; j < i * 2; j++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Output:

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

17. Plus pattern program in Java

The plus pattern has the shape of the mathematical plus sign (+).

  *
  *
*****
  *
  *

Here is complete code to create plus pattern program in Java:

public class plus {
  public static void main(String[] args) {
    // size of plus, use odd number
    int size = 5;

    for (int i = 0; i < size; i++) {
      for (int j = 0; j < size; j++) {
        // print only stars in middle row
        if (i == size / 2) {
          System.out.print("*");
        }
        // other than middle row, print star only at index size/2
        else {
          if (j == size / 2) {
            System.out.print("*");
          } else {
            System.out.print(" ");
          }
        }
      }
      System.out.println();
    }
  }
}

Output:

  *
  *
*****
  *
  *

18. Cross pattern program in Java

The cross pattern has the shape of the mathematical cross sign (X).

*   *
 * * 
  *  
 * * 
*   *

Here is complete code to create cross pattern program in Java:

public class cross {
  public static void main(String[] args) {
    // size of cross, use odd number
    int size = 5;

    for (int i = 0; i < size; i++) {
      for (int j = 0; j < size; j++) {
        if (i==j || i+j==size-1) {
          System.out.print("*");
        } else {
          System.out.print(" ");
        }
      }
      System.out.println();
    }
  }
}

Output:

*   *
 * *
  *
 * *
*   *

We have seen 18 star patterns till now let's see some number patterns.

19. Left triangle number pattern

Here is complete code to create a left triangle number pattern program in Java:

public class leftTrianlge {
  public static void main(String[] args) {

    int size = 5;
    // loop to print the pattern
    for (int i = 0; i < size; i++) {
      // print column
      for (int j = 0; j <= i; j++) {
        System.out.print(j+1);
      }
      System.out.println();
    }
  }
}

Output:

20. Right triangle number pattern

Here is complete code to create the right triangle number pattern program in Java:

public class rightTrianlge {
  public static void main(String[] args) {

    int size = 5;
    // loop to print the pattern
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 1; j < size - i; j++) {
        System.out.print(" ");
      }
      // print number
      for (int k = 0; k <= i; k++) {
        System.out.print(k+1);
      }
      System.out.println();
    }
  }
}

Output:

21. Number pyramid pattern

The number pyramid pattern has the shape of the mathematical number pyramid.

Here is complete code to create number pyramid pattern program in Java:

public class numberPyramid {
  // pyramid stnumberar pattern
  public static void main(String[] args) {

    int size = 5;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < size - i - 1; j++) {
        System.out.print(" ");
      }
      // print number
      for (int k = 0; k < 2 * i + 1; k++) {
        System.out.print(k+1);
      }
      System.out.println();
    }
  }
}

Output:

22. Number pyramid reverse pattern

The number pyramid reverse pattern has the shape of the mathematical number pyramid in reverse order.

Here is complete code to create a number pyramid reverse pattern in Java:

public class reverseNumberPyramid {
  public static void main(String[] args) {
    
    int size = 5;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // print number
      for (int k = 0; k < 2 * (size - i) - 1; k++) {
        System.out.print(k+1);
      }
      System.out.println();
    }
  }
}

Output:

23. Hollow number pyramid pattern

The hollow number pyramid pattern has the shape of the mathematical number pyramid with hollow inside.

Here is complete code to create hollow number pyramid pattern in Java:

public class hollowNumberPyramid {
  public static void main(String[] args) {

    int size = 5;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < size - i - 1; j++) {
        System.out.print(" ");
      }
      // print number
      int num = 1;
      for (int k = 0; k < 2 * i + 1; k++) {
        if (i == 0 || i == size - 1) {
          System.out.print(num++);
        } else {
          if (k == 0 || k == 2 * i) {
            System.out.print(num++);
          } else {
            System.out.print(" ");
          }
        }
      }
      System.out.println();
    }
  }
}

Output:

24. Number diamond pattern

The number diamond pattern has the shape of the diamond made of numbers.

Here is complete code to create number diamond pattern in Java:

public class numberDiamond {
  public static void main(String[] args) {
    int size = 5;
    int num = 1;
    // upside pyramid
    for (int i = 1; i <= size; i++) {
      // printing spaces
      for (int j = size; j > i; j--) {
        System.out.print(" ");
      }
      // printing number
      for (int k = 0; k < i * 2 - 1; k++) {
        System.out.print(num++);
      }
      // set the number to 1
      num = 1;
      System.out.println();
    }
    // downside pyramid
    for (int i = 1; i <= size - 1; i++) {
      // printing spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // printing number
      for (int k = (size - i) * 2 - 1; k > 0; k--) {
        System.out.print(num++);
      }
      // set num to 1
      num = 1;
      System.out.println();
    }
  }
}

Output:

25. Hollow number diamond pattern

The hollow number diamond pattern has the shape of the diamond made of numbers with hollow inside.

Here is complete code to create hollow number diamond pattern program in Java:

public class hollowDiamond {
  public static void main(String[] args) {
    int size = 5, num = 1;
    // upside pyramid
    for (int i = 1; i <= size; i++) {
      // printing spaces
      for (int j = size; j > i; j--) {
        System.out.print(" ");
      }
      // printing number
      for (int k = 0; k < i * 2 - 1; k++) {
        if (k == 0 || k == 2 * i - 2) {
          System.out.print(num++);
        } else {
          System.out.print(" ");
        }
      }
      // set the number to 1
      num = 1;
      System.out.println();
    }
    // downside triangle
    for (int i = 1; i < size; i++) {
      // printing spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // printing number
      for (int k = (size - i) * 2 - 1; k >= 1; k--) {
        if (k == 1 || k == (size - i) * 2 - 1) {
          System.out.print(num++);
        } else {
          System.out.print(" ");
        }
      }
      // set the number to 1
      num = 1;
      System.out.println();
    }
  }
}

Output:

Let's now create some patterns that use alphabets instead of stars or numbers.

26. Alphabet pyramid pattern

The alphabet pyramid pattern has the shape of the pyramid made of alphabets.

    A
   ABC
  ABCDE
 ABCDEFG
ABCDEFGHI

Here is complete code to create alphabet pyramid pattern program in Java:

public class alphabetPyramid {
  // pyramid alphabet pattern
  public static void main(String[] args) {

    int size = 5, alpha = 65;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < size - i - 1; j++) {
        System.out.print(" ");
      }
      // print alphabets
      for (int k = 0; k < 2 * i + 1; k++) {
        System.out.print((char)(alpha+k));
      }
      System.out.println();
    }
  }
}

Output:

    A
   ABC
  ABCDE
 ABCDEFG
ABCDEFGHI

27. Reverse alphabet pyramid pattern

The reverse alphabet pyramid pattern has the shape of a reversed pyramid made of alphabets.

ABCDEFGHI
 ABCDEFG
  ABCDE
   ABC
    A

Here is complete code to create reverse alphabet pyramid Java pattern program:

public class reverseAlphabetPyramid {
  public static void main(String[] args) {
    // size of the square
    int size = 5, alpha = 65;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // print alphabets
      for (int k = 0; k < 2 * (size - i) - 1; k++) {
        System.out.print((char) (alpha + k));
      }
      System.out.println();
    }
  }
}

Output:

ABCDEFGHI
 ABCDEFG
  ABCDE
   ABC
    A

28. Hollow alphabet pyramid pattern

The hollow alphabet pyramid pattern has the shape pyramid hollow inside which is made of alphabets.

    A
   B C
  D   E
 F     G
HIJKLMNOP

Here is complete code to create a hollow alphabet pyramid Java pattern program:

public class hollowAlphabetPyramid {
  public static void main(String[] args) {
    
    int size = 5, alpha = 65, num = 0;
    for (int i = 0; i < size; i++) {
      // print spaces
      for (int j = 0; j < size - i - 1; j++) {
        System.out.print(" ");
      }
      // print alphabets
      for (int k = 0; k < 2 * i + 1; k++) {
        if (i == 0 || i == size - 1) {
          System.out.print((char)(alpha+num++));
        } else {
          if (k == 0 || k == 2 * i) {
            System.out.print((char)(alpha+num++));
          } else {
            System.out.print(" ");
          }
        }
      }
      System.out.println();
    }
  }
}

Output:

    A
   B C
  D   E
 F     G
HIJKLMNOP

29. Alphabet diamond pattern

The alphabet diamond pattern has the shape of a diamond made of alphabets.

    A
   ABC
  ABCDE
 ABCDEFG
ABCDEFGHI
 ABCDEFG
  ABCDE
   ABC
    A

Here is complete code to create alphabet diamond Java pattern program:

public class alphabetDiamond {
  public static void main(String[] args) {
    int size = 5;
    int alpha = 65;
    int num = 0;
    // upside pyramid
    for (int i = 1; i <= size; i++) {
      // printing spaces
      for (int j = size; j > i; j--) {
        System.out.print(" ");
      }
      // printing alphabets
      for (int k = 0; k < i * 2 - 1; k++) {
        System.out.print((char)(alpha+num++));
      }
      // set the number to 0
      num = 0;
      System.out.println();
    }
    // downside pyramid
    for (int i = 1; i <= size - 1; i++) {
      // printing spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // printing alphabets
      for (int k = (size - i) * 2 - 1; k > 0; k--) {
        System.out.print((char)(alpha+num++));
      }
      // set num to 0
      num = 0;
      System.out.println();
    }
  }
}

Output:

    A
   ABC
  ABCDE
 ABCDEFG
ABCDEFGHI
 ABCDEFG
  ABCDE
   ABC
    A

30. Hollow alphabet diamond pattern

The hollow alphabet diamond pattern has the shape of a diamond hollow inside which is made of alphabets.

    A
   A B
  A   B
 A     B
A       B
 A     B
  A   B
   A B
    A

Here is complete code to create hollow alphabet diamond Java pattern program:

public class hollowAlphabetDiamond {
  public static void main(String[] args) {
    int size = 5;
    int alpha = 65;
    int num = 0;
    // upside pyramid
    for (int i = 1; i <= size; i++) {
      // printing spaces
      for (int j = size; j > i; j--) {
        System.out.print(" ");
      }
      // printing alphabets
      for (int k = 0; k < i * 2 - 1; k++) {
        if (k == 0 || k == 2 * i - 2) {
          System.out.print((char)(alpha+num++));
        } else {
          System.out.print(" ");
        }
      }
      // set the number to 0
      num = 0;
      System.out.println();
    }
    // downside triangle
    for (int i = 1; i < size; i++) {
      // printing spaces
      for (int j = 0; j < i; j++) {
        System.out.print(" ");
      }
      // printing alphabets
      for (int k = (size - i) * 2 - 1; k >= 1; k--) {
        if (k == 1 || k == (size - i) * 2 - 1) {
          System.out.print((char)(alpha+num++));
        } else {
          System.out.print(" ");
        }
      }
      // set the number to 0
      num = 0;
      System.out.println();
    }
  }
}

Output:

    A
   A B
  A   B
 A     B
A       B
 A     B
  A   B
   A B
    A

Conclusion

In this article, we have discussed 30 different java pattern programs in different ways. We used stars, numbers and, alphabets to create patterns.

Also, look at number patterns in Java and alphabet patterns in Java.