6 Pyramid Pattern In Java

In this tutorial, you will look at 6 different types of pyramid patterns in Java with their complete code.

Table Of Contents

Star Pyramid Pattern
Hollow Star Pyramid Pattern
Reverse Star Pyramid Pattern
Hollow Reverse Star Pyramid Pattern
Number Pyramid Pattern
Alphabet Pyramid Pattern

1. Star Pyramid Pattern in Java

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

Let's start with the simplest pyramid pattern, the star pyramid pattern. In this pattern, we print stars in a pyramid shape.

You can see each row has stars equal to the 2 * row number - 1. For example, the first row has 1 star, the second row has 3 stars, and so on.

Take the size of the pyramid from the user as input.
Call the starPyramid() method and pass the size as an argument.
Inside the starPyramid() method, we have two nested for loops.
The first for loop prints spaces before the stars, equal to size - row number.
The second for loop prints the stars, equal to 2 * row number - 1.
Print a new line after each row.

Example: Star Pyramid

import java.util.Scanner;

public class Pyramid {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter the size of the pyramid: ");
    int size = sc.nextInt();
    starPyramid(size);

    sc.close();
  }

  // function to print star pyramid
  static void starPyramid(int size) {
    // Outer loop for the number of rows
    for (int i = 1; i <= size; i++) {
      // first inner loop for spaces
      for (int j = 1; j <= size - i; j++) {
        System.out.print(" ");
      }
      // second inner loop for stars
      for (int k = 1; k <= 2*i -1; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Enter the size of the pyramid: 5
    *
   ***
  *****
 *******
*********

2. Hollow Star Pyramid Pattern

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

Now, let's look at the hollow star pyramid pattern.

Hollow star pyramid is the same as the star pattern but it has stars only at the boundaries.

Take the size of the pyramid from the user.
Call the hollowStarPyramid() method and pass the size as an argument.
Inside the hollowStarPyramid() method, we have two nested for loops.
The first for loop prints spaces just like the previous pattern.
The second for loop is interesting. It prints stars only if it's the first or last column or the last row.
Print a new line after each row.

Example: Hollow Star Pyramid

import java.util.Scanner;

public class Pyramid {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter the size of the pyramid: ");
    int size = sc.nextInt();
    hollowStarPyramid(size);

    sc.close();
  }

  // function to print hollow star pyramid
  static void hollowStarPyramid(int size) {
    // Outer loop for the number of rows
    for (int i = 1; i <= size; i++) {
      // first inner loop for spaces
      for (int j = 1; j <= size - i; j++) {
        System.out.print(" ");
      }
      // second inner loop for stars and intermediate spaces
      for (int k = 1; k <= 2*i -1; k++) {
        // check  if its first and last column or last row
        // print star otherwise print space
        if(k == 1 || k == 2*i -1 || i == size)
          System.out.print("*");
        else
          System.out.print(" ");
      }
      System.out.println();
    }
  }
}

Enter the size of the pyramid: 5
    *
   * *
  *   *
 *     *
*********

3. Inverted Star Pyramid Pattern

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

Inverted star pyramid pattern looks like water image of the normal star pyramid pattern.

Here is the complete code to print the inverted star pyramid pattern.

Example: Inverted Star Pyramid

import java.util.Scanner;

public class Pyramid {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter the size of the pyramid: ");
    int size = sc.nextInt();
    invertStarPyramid(size);

    sc.close();
  }

  // function to print inverted star pyramid
  static void invertStarPyramid(int size) {
    // Outer loop for the number of rows
    for (int i = 1; i <= size; i++) {
      // first inner loop for spaces
      for (int j = 1; j <= i - 1; j++) {
        System.out.print(" ");
      }
      // second inner loop print star
      for (int k = 1; k <= 2 * (size - i) + 1; k++) {
        System.out.print("*");
      }
      System.out.println();
    }
  }
}

Enter the size of the pyramid: 5
*********
 *******
  *****
   ***
    *

4. Inverted Hollow Star Pyramid Pattern

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

Inverted hollow star pyramid pattern is the same as the inverted star pyramid pattern except that is hollow inside.

Here is the complete code to print the inverted hollow star pyramid pattern.

Example: Inverted Hollow Star Pyramid

import java.util.Scanner;

public class z {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter the size of the pyramid: ");
    int size = sc.nextInt();
    hollowInvertStarPyramid(size);

    sc.close();
  }

  // function to print inverted hollow star pyramid
  static void hollowInvertStarPyramid(int size) {
    // Outer loop for the number of rows
    for (int i = 1; i <= size; i++) {
      // first inner loop for spaces
      for (int j = 1; j <= i - 1; j++) {
        System.out.print(" ");
      }
      // second inner loop for stars and spaces
      for (int k = 1; k <= 2 * (size - i) + 1; k++) {
        // print star for first and last column and for first row
        if (k == 1 || k == 2 * (size - i) + 1 || i == 1) {
          System.out.print("*");
        } else {
          System.out.print(" ");
        }
      }
      System.out.println();
    }
  }
}

Enter the size of the pyramid: 5
*********
 *     *
  *   *
   * *
    *

5. Number Pyramid Pattern

Above we have seen Pyramid pattern using stars now let's look at Number pyramid pattern.

We have to follow the same logic as we did above but instead of printing star we have to print numbers.

Print numbers from 1 to i in a row and reset the counter to 1 for the next row.

Here is the complete code to print the number pyramid pattern.

Example: Number Pyramid

import java.util.Scanner;

public class Pyramid {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter the size of the pyramid: ");
    int size = sc.nextInt();
    numberPyramid(size);

    sc.close();
  }

  static void numberPyramid(int size) {
    // Outer loop for the number of rows
    for (int i = 1; i <= size; i++) {
      // first inner loop for spaces
      for (int j = 1; j <= size - i; j++) {
        System.out.print(" ");
      }
      // second inner loop for printing numbers
      for (int k = 1; k <= 2 * i - 1; k++) {
        System.out.print(k);
      }
      System.out.println();
    }
  }
}

Enter the size of the pyramid: 5
    1
   123
  12345
 1234567
123456789

6. Alphabet Pyramid Pattern

    A
   ABC
  ABCDE
 ABCDEFG
ABCDEFGHI

Just like the number pattern with a little tweak you can create Alphabet pyramid pattern.

Just add 64 to the counter and typecast it to char to print the alphabet.

Here is the complete code to print the alphabet pyramid pattern.

Example: Alphabet Pyramid

import java.util.Scanner;

public class Pyramid {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter the size of the pyramid: ");
    int size = sc.nextInt();
    alphabetPyramid(size);

    sc.close();
  }

  static void alphabetPyramid(int size) {
    // Outer loop for the number of rows
    for (int i = 1; i <= size; i++) {
      // first inner loop for spaces
      for (int j = 1; j <= size - i; j++) {
        System.out.print(" ");
      }
      // second inner loop for printing numbers
      for (int k = 1; k <= 2 * i - 1; k++) {
        System.out.print((char) (k + 64));
      }
      System.out.println();
    }
  }
}

Enter the size of the pyramid: 5
    A
   ABC
  ABCDE
 ABCDEFG
ABCDEFGHI