Star Program in Java
By solving the patterns, we can develop our coding skills and logical thinking. Mostly each pattern program uses two or more loops. Loops' number depends on the complexity of logic. In these loops, the first loop work for rows and the second loop work for columns.
Let’s see some star patterns in java.
1. Right Triangle Pattern without space between stars
public class RightTriangle{
public static void main(String args[]){
// i works for rows
// j works for columns
int i, j, m = 6; // m = number of rows to be printed
for(i = 1;i <= m;i++){
for(j = 1;j <= i;j++){
// for not getting space between stars, we do not use any space after a star
System.out.print("*");
}
System.out.println();
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java1.png)
2. Right Triangle pattern with space between stars
public class RightTriangle{
public static void main(String args[]){
// i works for rows
// j works for columns
int i, j, m = 6; // m = number of rows to be printed
for( i = 1;i <= m;i++){
for(j = 1;j <= i;j++){
// for getting space between stars, we used a space after a star
System.out.print("* ");
}
System.out.println();
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java2.png)
3. Square Pattern Using stars
public class SquarePattern{
public static void main(String args[]){
for(int i = 1;i <= 5;i++){
for(int j = 1;j <= 5;j++){
System.out.print("* "); // Give space
}
System.out.println();
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java3.png)
4. Decreasing Triangle Patterns Using Stars
public class DecreasingTraianglePattern{
public static void main(String args[]){
for(int i = 1;i <= 5;i++){
for(int j = i;j <= 5;j++){
System.out.print("* ");
}
System.out.println();
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java4.png)
5. Hill Pattern Using stars
public class HillPattern{
public static void main(String args[]){
int n = 5;
for(int i = 1;i <= n;i++){
for(int j = i;j <= n;j++){
System.out.print(" ");
}
for(int j = 1;j < i;j++){
System.out.print("* ");
}
for(int j = 1;j <= i;j++){
System.out.print("* ");
}
System.out.println();
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java5.png)
6. Reverse Hill Pattern Using stars
public class ReverseHillPattern{
public static void main(String args[]){
int n = 5;
for(int i = 1;i <= n;i++){
for(int j = 1;j <= i;j++){
System.out.print(" ");
}
for(int j = i;j < n;j++){
System.out.print("* ");
}
for(int j = i;j <= n;j++){
System.out.print("* ");
}
System.out.println();
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java6.png)
7. Reverse Hill Pattern Using stars
public class ReverseHillPattern {
public static void main(String[] args) {
int size = 5;
for (int i = 1; i <= size; i++) {
for (int j = size; j > i; j--) {
System.out.print(" ");
}
for (int k = 0; k < i * 2 - 1; k++) {
System.out.print("* ");
}
System.out.println();
}
for (int i = 1; i <= size - 1; i++) {
for (int j = 0; j < i; j++) {
System.out.print(" ");
}
for (int k = (size - i) * 2 - 1; k > 0; k--) {
System.out.print("* ");
}
System.out.println();
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java7.png)
8. Right Pascal Triangle Pattern Using Stars
public class RightPascalTriangle
{
public static void main(String[] args)
{
int i, j, rows = 5;
for (i= 0; i<= rows-1; i++)
{
for (j=0; j<=i; j++)
{
System.out.print("*"+ " ");
}
System.out.println("");
}
for (i=rows-1; i>=0; i--)
{
for(j=0; j <= i-1;j++)
{
System.out.print("*"+ " ");
}
System.out.println(" ");
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java8.png)
9. Right Pascal Triangle Pattern Using Stars
public class LeftPascalTriangle
{
public static void main(String[] args)
{
int i, j, k, rows = 5;
for (i= 1; i<= rows ; i++)
{
for (j=i; j <rows ;j++)
{
System.out.print(" ");
}
for (k=1; k<=i;k++)
{
System.out.print("*");
}
System.out.println("");
}
for (i=rows; i>=1; i--)
{
for(j=i; j<=rows;j++)
{
System.out.print(" ");
}
for(k=1; k<i ;k++)
{
System.out.print("*");
}
System.out.println("");
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java9.png)
10. Hallow Triangle Pattern
public class HallowTraianglePattern
{
public static void main(String[] args)
{
int i, j, k, m=5;
for (i=1; i<= m ; i++)
{
for (j = i; j < m ; j++)
{
System.out.print(" ");
}
for (k = 1; k <= (2*i -1) ;k++)
{
if(k==1 || i == m || k==(2*i-1))
{
System.out.print("*");
}
else
{
System.out.print(" ");
}
}
System.out.println("");
}
}
}
Output:
![Star Program in Java](https://static.tutorialandexample.com/java/star-program-in-java10.png)