Java Program to Print Hollow Rectangle Star Pattern

Write a Java Program to print hollow rectangle star pattern using for loop. This Java rectangle star example uses nested for loop to iterate the rectangle rows and columns. The if-else condition check whether it is a rectangle first and last row or column. If it is true, print star; otherwise, print empty space.

package ShapePrograms;

import java.util.Scanner;

public class HollowRectangle1 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Hollow Rectangle Rows & Columns = ");
		int rows = sc.nextInt();
		int columns = sc.nextInt();
		
		System.out.println("Printing Hollow Rectangle Star Pattern");
		
		for (int i = 0; i < rows; i++ ) 
		{
			for (int j = 0 ; j < columns; j++ ) 
			{
				if (i == 0 || i == rows - 1 || j == 0 || j == columns - 1) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}
			}
			System.out.println();
		}
	}
}

In this Java hollow rectangle star pattern program, we replaced the nested for loop with while loops.

package ShapePrograms;

import java.util.Scanner;

public class HollowRectangle2 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Hollow Rectangle Rows & Columns = ");
		int rows = sc.nextInt();
		int columns = sc.nextInt();
		
		System.out.println("-- Printing Hollow Rectangle Star Pattern --");
		int i = 0; 
		while (i < rows ) 
		{
			int j = 0 ; 
			while(j < columns ) 
			{
				if (i == 0 || i == rows - 1 || j == 0 || j == columns - 1) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}
				j++ ;
			}
			System.out.println();
			i++;
		}
	}
}

Enter Hollow Rectangle Rows & Columns = 8 15
-- Printing Hollow Rectangle Star Pattern --
***************
*             *
*             *
*             *
*             *
*             *
*             *
***************

Java Program to Print Hollow Rectangle Star Pattern using do while loop

package ShapePrograms;

import java.util.Scanner;

public class HollowRectangle3 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Hollow Rectangle Rows & Columns = ");
		int rows = sc.nextInt();
		int columns = sc.nextInt();
		
		System.out.println("-- Printing Hollow Rectangle Star Pattern --");
		int j, i = 0; 
		do
		{
			j = 0 ; 
			do
			{
				if (i == 0 || i == rows - 1 || j == 0 || j == columns - 1) {
					System.out.print("*");
				}
				else {
					System.out.print(" ");
				}
			} while(++j < columns ) ;
			System.out.println();
		} while (++i < rows ) ;
	}
}

Enter Hollow Rectangle Rows & Columns = 10 20
-- Printing Hollow Rectangle Star Pattern --
********************
*                  *
*                  *
*                  *
*                  *
*                  *
*                  *
*                  *
*                  *
********************

This Java code prints the hollow rectangle pattern of the user-entered symbol. Furthermore, we also created a HollowRectanglePattern function that prints the hollow rectangle pattern.

package ShapePrograms;

import java.util.Scanner;

public class HollowRectangle4 {
	private static Scanner sc;
	
	public static void main(String[] args) {
		sc = new Scanner(System.in);
		
		System.out.print("Enter Hollow Rectangle Rows & Columns = ");
		int rows = sc.nextInt();
		int columns = sc.nextInt();
		
		System.out.print("Enter Character for Hollow Rectangle Pattern = ");
		char ch = sc.next().charAt(0);
		
		System.out.println("Printing Hollow Rectangle Pattern");
		HollowRectanglePattern(rows, columns, ch);	
	}
	
	public static void HollowRectanglePattern(int rows, int columns, char ch) {
		for (int i = 0; i < rows; i++ ) 
		{
			for (int j = 0 ; j < columns; j++ ) 
			{
				if (i == 0 || i == rows - 1 || j == 0 || j == columns - 1) {
					System.out.print(ch);
				}
				else {
					System.out.print(" ");
				}
			}
			System.out.println();
		}
	}
}

Enter Hollow Rectangle Rows & Columns = 14 30
Enter Character for Hollow Rectangle Pattern = #
Printing Hollow Rectangle Pattern
##############################
#                            #
#                            #
#                            #
#                            #
#                            #
#                            #
#                            #
#                            #
#                            #
#                            #
#                            #
#                            #
##############################