Example: Diamond Pattern Printer in Java

// Diamond Pattern Printer
import java.util.Scanner;

// Main class containing the entry point of the program
public class Main {
    public static void main(String[] args) {
        // Step 1: Initialize Scanner for user input
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter the number of rows for the upper half of the diamond (e.g., 5): ");
        int n = scanner.nextInt(); // n represents the height of the upper half (including middle)

        // Step 2: Print the Upper Half of the Diamond
        // This loop iterates for each row in the upper half, from 1 to n
        for (int i = 1; i <= n; i++) {
            // Step 2.1: Print leading spaces
            // The number of spaces decreases as 'i' increases
            for (int j = 1; j <= n - i; j++) {
                System.out.print(" ");
            }
            // Step 2.2: Print stars
            // The number of stars increases (2*i - 1) as 'i' increases
            for (int j = 1; j <= 2 * i - 1; j++) {
                System.out.print("*");
            }
            // Step 2.3: Move to the next line after completing a row
            System.out.println();
        }

        // Step 3: Print the Lower Half of the Diamond
        // This loop iterates for each row in the lower half, from n-1 down to 1
        for (int i = n - 1; i >= 1; i--) {
            // Step 3.1: Print leading spaces
            // The number of spaces increases as 'i' decreases
            for (int j = 1; j <= n - i; j++) {
                System.out.print(" ");
            }
            // Step 3.2: Print stars
            // The number of stars decreases (2*i - 1) as 'i' decreases
            for (int j = 1; j <= 2 * i - 1; j++) {
                System.out.print("*");
            }
            // Step 3.3: Move to the next line after completing a row
            System.out.println();
        }

        // Step 4: Close the scanner to release resources
        scanner.close();
    }
}