Java Program to Print Square Star Pattern

 Example 1: Star square pattern without diagonals

/ Java Program to Print Square Pattern

// Case 1: Hollow rectangle

// Importing input output classes

import java.io.*;

// Main class

class GFG {

// Method 1

// To print hollow rectangle

static void print_rectangle(int k, int l)

{

int a, b;

// Nested for loops for iterations

// Outer loop for rows

for (a = 1; a <= k; a++) {

// Inner loop for columns

for (b = 1; b <= l; b++) {

// Condition check using logical OR operator

// over rows and columns positions

// if found at circumference of rectangle

if (a == 1 || a == k || b == 1 || b == l)

// Print the star pattern

System.out.print("*");

else

// Rest inside square print the empty

// spaces

System.out.print(" ");

}

// By now we are done with only 1 row so

// New line

System.out.println();

}

}

// Method 2

// Main driver method

public static void main(String args[])

{

// Declaring and initializing rows and columns

// For square row = columns

// Custom input initialization values

int rows = 8, columns = 22;

// Calling the method1 to print hollow rectangle

// pattern

print_rectangle(rows, columns);

}

}

Example 2: Star square pattern with diagonals 

// Java Program to Print Square Star pattern

// Case: Primary and secondary diagonal Rectangle Pattern

import java.io.*;

// Mai class

class GFG {

// Method 1

// To print square with primary and secondary diagonal

static void print_squaredi(int k)

{

int a, b;

// Nested 2 for loops for Matrix printing

// Outer loop for rows

for (a = 1; a <= k; a++) {

// Inner loop for columns

for (b = 1; b <= k; b++) {

// Condition check using OR operator where

// 1. Printing star as per first 4 checks

// on the circumference of rectangle

// 2. Fifth check is for diagonals

if (a == 1 || a == k || b == 1 || b == k

|| a == b || b == (k - a + 1))

// Print the star pattern

System.out.print("*");

else

// Print the white spaces

System.out.print(" ");

}

// By now we are over with one row so

// new line

System.out.println();

}

}

// Method 2

// Main driver method

public static void main(String args[])

{

// This time taking square so only one variable

// needs to be declared

// Custom input entry

int rows = 12;

// calling the method1 to print

// square pattern with diagonal

print_squaredi(rows);

}

}