Print Diamond Shape Star Pattern in Java

Programming is always a fun and creative task. The more creative you can think the better programmer you will become. However, programming isn’t always about solving problems sometimes there’s also a fun aspect to it which makes it way more satisfying. If you are a programmer then you might have already played with patterns, strings, etc multiple times. Well, it’s also like that you are already familiar with printing patterns. So in today’s article, we will create a program to Print Diamond Shape Star Pattern in Java. With the help of this program, you will be able to print a diamond using the java language. Practising these types of questions also helps to get an upper edge in Competitive Programming.

We will be showing you different ways of printing diamond shape pattern in Java so that you can use whatever method you like to impress your classmates, friends or even your crush if he/she likes programming. So open up your IDE and let’s get started real quick. Once you understand the logic practice this program on your own to make your brain work in a problem-solving way. This is a somewhat hard question you might get asked in an interview so make sure to practice it on your own after reading this article.

Also Read: How to Install Java JDK JRE on Windows 11

Java Program To Print Diamond Shape Star Pattern With

1) do-while Loop

// Java program to Print Diamond Star Pattern
// Using do-while loop

// Importing input output classes
import java.io.*;

// Main class
public class TechDecodeTutorials {

    // Main driver method
    public static void main(String[] args)
    {
        // Declaring and initializing variables

        // Variable initialized to the row where max star
        // should be there as after that they decreases to
        // give diamond pattern
        int number = 7;

        // Diamond starting with single star in first row,so
        // initialized
        int m = 1;

        // Columnar printing
        int n;

        // Outer loop 1
        // Prints the first half diamond
        do {
            n = 1;

            // Inner loop 1
            // Prints space until ++n <= number - m + 1 is
            // false
            do {
                // Print whitespace between
                System.out.print(" ");

            }

            // Condition for inside do-while loop 1
            while (++n <= number - m + 1);

            // Now
            n = 1;

            // Inner loop 2
            // Prints star until ++n <= m * 2 - 1 is false

            do {

                // Print star
                System.out.print("*");
            }

            // Condition for iner do-while loop 2
            while (++n <= m * 2 - 1);

            // A new row requires a new line
            System.out.println();

        }

        // Condition for outer do-while loop 1
        while (++m <= number);

        // Now we are done with printing the upper half
        // diamond.

        // Note: Not to print the bottom row again in lower
        // half diamond printing Hence variable t be
        // initialized should one lesser than number
        m = number - 1;

        // Outer loop 2
        // Prints the second half diamond
        do {
            n = 1;

            // Inner loop 1
            // Prints space until ++n <= number - m + 1 is
            // false
            do {
                // Print whitespace between
                System.out.print(" ");

            } while (++n <= number - m + 1);

            n = 1;

            // Inner loop 2
            // Prints star until ++n <= m * 2 - 1 is false
            do {
                // Prints star
                System.out.print("*");

            } while (++n <= m * 2 - 1);

            // By now done with one row of lower diamond
            // printing so a new line is required
            System.out.println();

        }

        // Condition for outer do-while loop 2
        while (--m > 0);
    }
}

Output

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

2) while Loop

// Java program to print diamond star pattern
// Using while loop

// Importing input output classes
import java.io.*;

// Main class
public class TechDecodeTutorials {

    // Main driver method
    public static void main(String[] args)
    {

        // Declaring and initializing variables

        // Variable initialized to the row where max star
        // should be there as after that they decreases to
        // give diamond pattern
        int number = 7;

        // Diamond starting with single star in first row
        int m = 1;

        // Columnar printing
        int n;

        // Outer loop 1
        // Prints the first half diamond

        // Condition holding true till
        // number of rows initialized
        while (m <= number) {
            n = 1;

            // Inner loop 1
            // Prints space until n++ <= number - m is false
            while (n++ <= number - m) {

                // Print whitespaces inbetween
                System.out.print(" ");
            }

            n = 1;

            // Inner loop 2
            // Prints star until n++ <= m * 2 - 1 is false
            while (n++ <= m * 2 - 1) {

                // Print star
                System.out.print("*");
            }

            // By now we are done for above pyramid printing
            // ending line after each row
            System.out.println();

            // Incrementing as we want pyramid generation
            m++;
        }

        // Now we are done with printing the upper half
        // diamond.

        // Note: Not to print the bottom row again in lower
        // half diamond printing Hence variable t be
        // initialized should one lesser than number
        m = number - 1;

        // Outer loop 2
        // Prints the second half diamond
        while (m > 0) {
            n = 1;

            // Inner loop 1
            // Prints spaces until n++ <= number - m is
            // false
            while (n++ <= number - m) {

                // Print whitespace in between
                System.out.print(" ");
            }

            n = 1;

            // Inner loop 2
            // Prints star until n++ <= m * 2 - 1 is false
            while (n++ <= m * 2 - 1) {

                // Print star
                System.out.print("*");
            }

            // Ending line after each row
            System.out.println();

            // Decrementing as we want reverse pyramid
            // generation
            m--;
        }
    }
}

Output

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

3) Using for Loop

// Java program to print diamond star pattern
// Using for loop

// Importing input output classes
import java.io.*;

// Main class
public class TechDecodeTutorials {

    // Main driver method
    public static void main(String[] args)
    {

        // Declaring and initializing variables

        // Variable initialized to the row where max star
        // should be there as after that they decreases to
        // give diamond pattern
        int number = 7;

        int m, n;

        // Outer loop 1
        // prints the first half diamond
        for (m = 1; m <= number; m++) {

            // Inner loop 1 print whitespaces inbetween
            for (n = 1; n <= number - m; n++) {
                System.out.print(" ");
            }

            // Inner loop 2 prints star
            for (n = 1; n <= m * 2 - 1; n++) {
                System.out.print("*");
            }

            // Ending line after each row
            System.out.println();
        }

        // Outer loop 2
        // Prints the second half diamond
        for (m = number - 1; m > 0; m--) {

            // Inner loop 1 print whitespaces inbetween
            for (n = 1; n <= number - m; n++) {
                System.out.print(" ");
            }

            // Inner loop 2 print star
            for (n = 1; n <= m * 2 - 1; n++) {
                System.out.print("*");
            }

            // Ending line after each row
            System.out.println();
        }
    }
}

Output

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