Java Pattern Programs

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

public class HollowSquare {
public static void main(String[] args) {
int n = 5; // Size of the square
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
// Print '*' for the first and last row, and first and last column
if (i == 0 || i == n - 1 || j == 0 || j == n - 1) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println();
}
}
}

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

public class HollowPyramid {
public static void main(String[] args) {
int n = 5; // Height of the pyramid
for (int i = 1; i <= n; i++) {
// Print spaces for alignment
for (int j = i; j < n; j++) {
System.out.print(" ");
}
// Print stars and spaces in the pyramid structure
for (int j = 1; j <= (2 * i - 1); j++) {
// Print '*' for the edges and the last row
if (j == 1 || j == (2 * i - 1) || i == n) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println();
}
}
}

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

public class HollowDiamond {
public static void main(String[] args) {
int n = 5; // Number of rows for the top half of the diamond
// Top half of the diamond
for (int i = 1; i <= n; i++) {
// Print spaces before stars
for (int j = i; j < n; j++) {
System.out.print(" ");
}
// Print stars and spaces
for (int j = 1; j <= (2 * i - 1); j++) {
if (j == 1 || j == (2 * i - 1)) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println();
}
// Bottom half of the diamond
for (int i = n - 1; i >= 1; i--) {
// Print spaces before stars
for (int j = n; j > i; j--) {
System.out.print(" ");
}
// Print stars and spaces
for (int j = 1; j <= (2 * i - 1); j++) {
if (j == 1 || j == (2 * i - 1)) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println();
}
}
}

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

public class ButterflyPattern {
public static void main(String[] args) {
int n = 4; // Number of rows
// Upper half of the butterfly
for (int i = 1; i <= n; i++) {
// Print the first part of the stars
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
// Print the spaces in between
for (int j = 1; j <= (2 * (n - i)); j++) {
System.out.print(" ");
}
// Print the second part of the stars
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println();
}

// Lower half of the butterfly
for (int i = n; i >= 1; i--) {
// Print the first part of the stars
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
// Print the spaces in between
for (int j = 1; j <= (2 * (n - i)); j++) {
System.out.print(" ");
}
// Print the second part of the stars
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println();
}
}
}

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

public class RightPascalsTriangle {
public static void main(String[] args) {
int n = 5; // Number of rows
// Upper half of Pascal's Triangle
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println();
}
// Lower half of Pascal's Triangle
for (int i = n - 1; i >= 1; i--) {
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println();
}
}
}

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

public class LeftPascalsTriangle {
public static void main(String[] args) {
int n = 5; // Number of rows
// Upper half of Pascal's Triangle
for (int i = 1; i <= n; i++) {
// Print leading spaces
for (int j = 1; j <= n - i; j++) {
System.out.print(" ");
}
// Print stars
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println();
}
// Lower half of Pascal's Triangle
for (int i = n - 1; i >= 1; i--) {
// Print leading spaces
for (int j = 1; j <= n - i; j++) {
System.out.print(" ");
}
// Print stars
for (int j = 1; j <= i; j++) {
System.out.print("*");
}
System.out.println();
}
}
}

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

public class HourglassPattern {
public static void main(String[] args) {
int n = 5; // Number of rows
// Upper half of the hourglass
for (int i = 0; i < n; i++) {
// Print leading spaces
for (int j = 0; j < i; j++) {
System.out.print(" ");
}
// Print stars
for (int j = 0; j < (2 * (n - i) - 1); j++) {
System.out.print("*");
}
System.out.println();
}
// Lower half of the hourglass
for (int i = 1; i < n; i++) {
// Print leading spaces
for (int j = 0; j < n - i - 1; j++) {
System.out.print(" ");
}
// Print stars
for (int j = 0; j < (2 * (i + 1) - 1); j++) {
System.out.print("*");
}
System.out.println();
}
}
}

A
AB
ABC
ABCD
ABCDE

public class AlphabetTrianglePattern {
public static void main(String[] args) {
int n = 5; // Number of rows
// Loop for each row
for (int i = 1; i <= n; i++) {
// Loop to print the alphabet letters
for (char j = 'A'; j < 'A' + i; j++) {
System.out.print(j);
}
System.out.println();
}
}
}

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

public class ZigZagPattern {
public static void main(String[] args) {
int n = 7; // Number of columns
// Loop to print the upper part of the zig-zag pattern
for (int i = 1; i <= 3; i++) {
for (int j = 1; j <= n; j++) {
if (j % 2 != 0) {
System.out.print("* ");
} else {
System.out.print(" ");
}
}
System.out.println();
}

// Loop to print the bottom part of the zig-zag pattern
for (int i = 1; i <= 3; i++) {
for (int j = 1; j <= n; j++) {
if (j % 2 == 0) {
System.out.print("* ");
} else {
System.out.print(" ");
}
}
System.out.println();
}
}
}

1
01
101
0101
10101

public class BinaryTrianglePattern {
public static void main(String[] args) {
int n = 5; // Number of rows
for (int i = 1; i <= n; i++) {
for (int j = 1; j <= i; j++) {
if ((i + j) % 2 == 0) {
System.out.print("1");
} else {
System.out.print("0");
}
}
System.out.println();
}
}
}