Program to print Hollow rectangle and square star pattern

Karmehavannan

6 years ago

Program to Print Hollow rectangle or square star pattern

In this article, we will discuss the concept of Program to Print Hollow rectangle or square star pattern in Java programming language

In this post, we are going to learn How to write a Java program to print Hollow rectangle or square star pattern using for loop, while loop and Do-while loops with example programs

Print Hollow rectangle and square star pattern in java — Hollow pattern

Program 1

Print Hollow rectangle or square star pattern

Using for loop

This program allows the user to enter the number of rows and columns and then it will display Hollow rectangle and square pattern using for loop in Java language

import java.util.Scanner;
class Hollow_RectanglePat{
public static void main(String args[]){
int rows,columns;//declare variable size
    Scanner scan=new Scanner(System.in); 
    //create a scanner object for input
System.out.print("Enter the nunber of rows: ");
rows=scan.nextInt();
//get input from the user for row

System.out.print("Enter the nunber of rows: ");
columns=scan.nextInt();
//get input from the user for coloum


for (int i=1; i<=rows; i++){
    for (int j=1; j<=columns; j++){
    if(i==1||i==rows||j==1||j==columns){
        System.out.print("*");
    }else{
        System.out.print(" ");
    }
    
}
    System.out.print("\n");
}
}
}

When the above code is executed, it produces the following results

Program 2

Using while loop

This program allows the user to enter the number of rows and columns and then it will display Hollow rectangle and square pattern using while loop in Java language

import java.util.Scanner;
class Hollow_RectanglePat1{
public static void main(String args[]){
int rows,columns;//declare variable size
    Scanner scan=new Scanner(System.in); 
    //create a scanner object for input
System.out.print("Enter the nunber of rows: ");
rows=scan.nextInt();
//get input from the user for row

System.out.print("Enter the nunber of rows: ");
columns=scan.nextInt();
//get input from the user for coloum

int i=1;
while( i<=rows){
    int j=1;
    while( j<=columns){
    if(i==1||i==rows||j==1||j==columns){
        System.out.print("*");
    }else{
        System.out.print(" ");
    }
     j++;
    
}
    System.out.print("\n");
    i++;
}
}
}

When the above code is executed, it produces the following results

Program 3

Using the do-while loop

This program allows the user to enter the number of rows and columns and then it will display Hollow rectangle and square pattern using the do-while loop in Java language

import java.util.Scanner;
class Hollow_RectanglePat2{
public static void main(String args[]){
int rows,columns;//declare variable size
    Scanner scan=new Scanner(System.in); 
    //create a scanner object for input
System.out.print("Enter the nunber of rows: ");
rows=scan.nextInt();
//get input from the user for row

System.out.print("Enter the nunber of rows: ");
columns=scan.nextInt();
//get input from the user for coloum

int i=1;
do{
    int j=1;
    do{
    if(i==1||i==rows||j==1||j==columns){
        System.out.print("*");
    }else{
        System.out.print(" ");
    }
     j++;
    
}while( j<=columns);
    System.out.print("\n");
    i++;
}while( i<=rows);
}
}

When the above code is executed, it produces the following results