Star, number, and character patterns are the most asked Java Pattern Programs in interviews to check your logical and coding skills. Pattern programs in Java help you to sharpen your looping concepts(for loop). To learn pattern programs, you must have knowledge of Java Loops.
Patterns Programs in Java
Java Pattern Programs
Here, you will find the top 25 Java pattern programs with their proper code and explanation.
- Square Hollow Pattern
- Number triangle Pattern
- Number-increasing Pyramid Pattern
- Number-increasing reverse Pyramid Pattern
- Number-changing Pyramid Pattern
- Zero-One triangle Pattern
- Palindrome triangle Pattern
- Rhombus Pattern
- Diamond Star Pattern
- Butterfly star Pattern
- Square fill Pattern
- Right Half Pyramid Pattern
- Reverse Right Half Pyramid Pattern
- Left Half Pyramid Pattern
- Reverse Left Half Pyramid Pattern
- Triangle star Pattern
- Reverse number triangle Pattern
- Mirror Image triangle Pattern
- Hollow triangle Pattern
- Hollow reverse triangle Pattern
- Hollow Diamond Pyramid
- Hollow Hourglass Pattern
- Pascal’s Triangle
- Right Pascal’s Triangle
- K Pattern
1. Square Hollow Pattern
Java
// Java Program to print pattern// Square hollow patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle number of rows for (i = 0; i < n; i++) { // inner loop to handle number of columns for (j = 0; j < n; j++) { // star will print only when it is in first // row or last row or first column or last // column if (i == 0 || j == 0 || i == n - 1 || j == n - 1) { System.out.print("*"); } // otherwise print space only. else { System.out.print(" "); } } System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
C#
// C# Program to print pattern Square hollow pattern using System; public class GFG{ // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle number of rows for (i = 0; i < n; i++) { // inner loop to handle number of columns for (j = 0; j < n; j++) { // star will print only when it is in first // row or last row or first column or last // column if (i == 0 || j == 0 || i == n - 1 || j == n - 1) { Console.Write("*"); } // otherwise print space only. else { Console.Write(" "); } } Console.WriteLine(); } } static public void Main (){ // Code int n = 6; printPattern(n); }} // This code is contributed by sankar. |
Output
****** * * * * * * * * ******
2. Number triangle Pattern
Java
// Java Program to print pattern// Number triangle patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle number of rows for (i = 1; i <= n; i++) { // inner loop to print space for (j = 1; j <= n - i; j++) { System.out.print(" "); } // inner loop to print star for (j = 1; j <= i; j++) { System.out.print(i + " "); } // print new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
C#
// C# Program to print pattern Number triangle pattern using System; public class GFG { // Function to demonstrate pattern static void printPattern(int n) { int i, j; // outer loop to handle number of rows for (i = 1; i <= n; i++) { // inner loop to print space for (j = 1; j <= n - i; j++) { Console.Write(" "); } // inner loop to print star for (j = 1; j <= i; j++) { Console.Write(i + " "); } // print new line for each row Console.WriteLine(); } } static public void Main() { // Code int n = 6; printPattern(n); }} // this code is contributed by lokesh |
Output
1
2 2
3 3 3
4 4 4 4
5 5 5 5 5
6 6 6 6 6 6
3. Number-increasing Pyramid Pattern
Java
// Java Program to print pattern// Number-increasing pyramid import java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle number of rows for (i = 1; i <= n; i++) { // inner loop to handle number of columns for (j = 1; j <= i; j++) { // printing column values upto the row // value. System.out.print(j + " "); } // print new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
1 1 2 1 2 3 1 2 3 4 1 2 3 4 5 1 2 3 4 5 6
4. Number-increasing reverse Pyramid Pattern
Java
// Java Program to print pattern// Number-increasing reverse pyramidimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle number of rows for (i = n; i >= 1; i--) { // inner loop to handle number of columns for (j = 1; j <= i; j++) { // printing column values upto the row // value. System.out.print(j + " "); } // print new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
1 2 3 4 5 6 1 2 3 4 5 1 2 3 4 1 2 3 1 2 1
5. Number-changing Pyramid Pattern
Java
// Java Program to print pattern// Number-changing pyramidimport java.util.*; // Java code for printing patternpublic class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; int num = 1; // outer loop to handle number of rows for (i = 1; i <= n; i++) { // inner loop to handle number of columns for (j = 1; j <= i; j++) { // printing value of num in each iteration. System.out.print(num + " "); // increasing the value of num. num++; } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
6. Zero-One Triangle Pattern
Java
// Java Program to print pattern// Zero-One triangleimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; //outer loop to handle number of rows for (i = 1; i <= n; i++) { //inner loop to handle number of columns for (j = 1; j <= i; j++) { // if the sum of (i+j) is even then print 1 if ((i + j) % 2 == 0) { System.out.print(1 + " "); } // otherwise print 0 else { System.out.print(0 + " "); } } //printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
1 0 1 1 0 1 0 1 0 1 1 0 1 0 1 0 1 0 1 0 1
7. Palindrome Triangle Pattern
Java
// Java Program to print pattern// Palindrome triangleimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle number of rows for (i = 1; i <= n; i++) { // inner loop to print the spaces for (j = 1; j <= 2 * (n - i); j++) { System.out.print(" "); } // inner loop to print the first part for (j = i; j >= 1; j--) { System.out.print(j + " "); } // inner loop to print the second part for (j = 2; j <= i; j++) { System.out.print(j + " "); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
1
2 1 2
3 2 1 2 3
4 3 2 1 2 3 4
5 4 3 2 1 2 3 4 5
6 5 4 3 2 1 2 3 4 5 6
8. Rhombus Pattern
Java
// Java Program to print// Rhombus patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; int num = 1; // outer loop to handle number of rows for (i = 1; i <= n; i++) { // inner loop to print spaces for (j = 1; j <= n - i; j++) { System.out.print(" "); } // inner loop to print stars for (j = 1; j <= n; j++) { System.out.print("*"); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
******
******
******
******
******
******
9. Diamond Star Pattern
Java
// Java Program to print// Diamond Star Patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; int num = 1; // outer loop to handle upper part for (i = 1; i <= n; i++) { // inner loop to print spaces for (j = 1; j <= n - i; j++) { System.out.print(" "); } // inner loop to print stars for (j = 1; j <= 2 * i - 1; j++) { System.out.print("*"); } System.out.println(); } // outer loop to handle lower part for (i = n-1; i >= 1; i--) { // inner loop to print spaces for (j = 1; j <= n - i; j++) { System.out.print(" "); } // inner loop to print stars for (j = 1; j <= 2 * i - 1; j++) { System.out.print("*"); } System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
*
***
*****
*******
*********
***********
*********
*******
*****
***
*
10. Butterfly Star Pattern
Java
// Java Program to print// Butterfly Patternimport java.util.*; // Java code for printing patternpublic class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; int num = 1; // outer loop to handle upper part for (i = 1; i <= n; i++) { // inner loop to print stars for (j = 1; j <= i; j++) { System.out.print("*"); } // inner loop to print spaces int spaces = 2 * (n - i); for (j = 1; j <= spaces; j++) { System.out.print(" "); } // inner loop to print stars for (j = 1; j <= i; j++) { System.out.print("*"); } System.out.println(); } // outer loop to handle lower part for (i = n; i >= 1; i--) { // inner loop to print stars for (j = 1; j <= i; j++) { System.out.print("*"); } // inner loop to print spaces int spaces = 2 * (n - i); for (j = 1; j <= spaces; j++) { System.out.print(" "); } // inner loop to print stars for (j = 1; j <= i; j++) { System.out.print("*"); } System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
* * ** ** *** *** **** **** ***** ***** ************ ************ ***** ***** **** **** *** *** ** ** * *
11. Square Fill Pattern
Java
// Java Program to print// Square fill patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle rows for (i = 0; i <= n; i++) { // inner loop to handle columns for (j = 0; j <= n; j++) { System.out.print("*"); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
******* ******* ******* ******* ******* ******* *******
12. Right Half Pyramid Pattern
Java
// Java Program to print// Pyramid patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle rows for (i = 1; i <= n; i++) { // inner loop to handle columns for (j = 1; j <= i; j++) { System.out.print("*"); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
* ** *** **** ***** ******
13. Reverse Right Half Pyramid Pattern
Java
// Java Program to print pattern// Reverse Right Half Pyramidimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle rows for (i = n; i >= 1; i--) { // inner loop to handle columns for (j = 1; j <= i; j++) { System.out.print("*"); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
****** ***** **** *** ** *
14. Left Half Pyramid Pattern
Java
// Java Program to print pattern// Left Half Pyramid patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle rows for (i = n; i >= 1; i--) { // inner loop to print spaces. for (j = 1; j < i; j++) { System.out.print(" "); } // inner loop to print stars. for (j = 0; j <= n - i; j++) { System.out.print("*"); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
*
**
***
****
*****
******
15. Reverse Left Half Pyramid Pattern
Java
// Java Program to print pattern// Reverse Left Half Pyramid import java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // calculating number of spaces int num = 2 * n - 2; // outer loop to handle rows for (i = n; i > 0; i--) { // inner loop to print spaces. for (j = 0; j < n - i; j++) { System.out.print(" "); } // Decrementing value of num after each loop num = num - 2; // inner loop to print stars. for (j = 0; j < i; j++) { System.out.print("*"); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
******
*****
****
***
**
*
16. Triangle Star Pattern
Java
// Java Program to print// Triangular Patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle rows for (i = 0; i < n; i++) { // inner loop to print spaces. for (j = n - i; j > 1; j--) { System.out.print(" "); } // inner loop to print stars. for (j = 0; j <= i; j++) { System.out.print("* "); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
*
* *
* * *
* * * *
* * * * *
* * * * * *
17. Reverse number Triangle Pattern
Java
// Java Program to print pattern// Reverse number triangleimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle rows for (i = 1; i <= n; i++) { // inner loop to print spaces. for (j = 1; j < i; j++) { System.out.print(" "); } // inner loop to print value of j. for (j = i; j <= n; j++) { System.out.print(j + " "); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
1 2 3 4 5 6
2 3 4 5 6
3 4 5 6
4 5 6
5 6
6
18. Mirror Image Triangle Pattern
Java
// Java Program to print pattern// Mirror Image of a triangleimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // Printing the upper part for (i = 1; i <= n; i++) { // inner loop to print spaces. for (j = 1; j < i; j++) { System.out.print(" "); } // inner loop to print value of j. for (j = i; j <= n; j++) { System.out.print(j + " "); } // printing new line for each row System.out.println(); } // Printing the lower part for (i = n - 1; i >= 1; i--) { // inner loop to print spaces. for (j = 1; j < i; j++) { System.out.print(" "); } // inner loop to print value of j. for (j = i; j <= n; j++) { System.out.print(j + " "); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
1 2 3 4 5 6
2 3 4 5 6
3 4 5 6
4 5 6
5 6
6
5 6
4 5 6
3 4 5 6
2 3 4 5 6
1 2 3 4 5 6
19. Hollow Triangle Pattern
Java
// Java Program to print // Hollow triangle patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j, k; // outer loop to handle rows for (i = 1; i <= n; i++) { // inner loop to print spaces. for (j = i; j < n; j++) { System.out.print(" "); } for (k = 1; k <= (2 * i - 1); k++) { // printing stars. if (k == 1 || i == n || k == (2 * i - 1)) { System.out.print("*"); } // printing spaces. else { System.out.print(" "); } } System.out.println(""); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
*
* *
* *
* *
* *
***********
20. Hollow Reverse Triangle Pattern
Java
// Java Program to print pattern// Reverse Hollow triangleimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j, k; // outer loop to handle rows for (i = n; i >= 1; i--) { // inner loop to print spaces. for (j = i; j < n; j++) { System.out.print(" "); } for (k = 1; k <= (2 * i - 1); k++) { // printing stars. if (k == 1 || i == n || k == (2 * i - 1)) { System.out.print("*"); } // printing spaces. else { System.out.print(" "); } } System.out.println(""); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
***********
* *
* *
* *
* *
*
21. Hollow Diamond Pyramid
Java
// Java Program to print Pattern// Hollow Diamond Starimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; int num = 1; // outer loop to handle upper part for (i = 1; i <= n; i++) { // inner loop to print spaces for (j = 1; j <= n - i; j++) { System.out.print(" "); } // inner loop to print stars for (j = 1; j <= 2 * i - 1; j++) { if (j == 1 || j == 2*i-1) System.out.print("*"); else System.out.print(" "); } System.out.println(); } // outer loop to handle lower part for (i = n-1; i >= 1; i--) { // inner loop to print spaces for (j = 1; j <= n - i; j++) { System.out.print(" "); } // inner loop to print stars for (j = 1; j <= 2 * i - 1; j++) { if (j == 1 || j == 2*i-1) System.out.print("*"); else System.out.print(" "); } System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
*
* *
* *
* *
* *
* *
* *
* *
* *
* *
*
22. Hollow Hourglass Pattern
Java
// Java Program to print pattern// Hollow Hourglass Patternimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // Printing the upper part for (i = 1; i <= n; i++) { // inner loop to print spaces. for (j = 1; j < i; j++) { System.out.print(" "); } // inner loop to print value of j. for (j = i; j <= n; j++) { if(j==i||j==n||i==1) System.out.print("* "); else System.out.print(" "); } // printing new line for each row System.out.println(); } // Printing the lower part for (i = n - 1; i >= 1; i--) { // inner loop to print spaces. for (j = 1; j < i; j++) { System.out.print(" "); } // inner loop to print value of j. for (j = i; j <= n; j++) { if(j==i||j==n||i==1) System.out.print("* "); else System.out.print(" "); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
* * * * * *
* *
* *
* *
* *
*
* *
* *
* *
* *
* * * * * *
23. Pascal’s Triangle
Java
// Java Program to implement// Pascal's Triangleimport java.util.*; class GFG { // Pascal function public static void printPascal(int n) { for (int i = 1; i <= n; i++) { for (int j = 0; j <= n - i; j++) { // for left spacing System.out.print(" "); } // used to represent x(i, k) int x = 1; for (int k = 1; k <= i; k++) { // The first value in a line is always 1 System.out.print(x + " "); x = x * (i - k) / k; } System.out.println(); } } // Driver code public static void main(String[] args) { int n = 4; printPascal(n); }} |
Output
1 1 1 1 2 1 1 3 3 1
24. Right Pascal’s Triangle
Java
// Java Program to print// Right Pascal’s Triangleimport java.util.*; // Java code for printing patternpublic class Main { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; int num = 1; // outer loop to handle upper part for (i = 1; i <= n; i++) { // inner loop to print stars for (j = 1; j <= i; j++) { System.out.print("* "); } System.out.println(); } // outer loop to handle lower part for (i = n-1; i >= 1; i--) { // inner loop to print stars for (j = 1; j <= i; j++) { System.out.print("* "); } System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 4; printPattern(n); }} |
Output
* * * * * * * * * * * * * * * *
25. K Pattern
Java
// Java Program to print pattern// Reverse Right Half Pyramidimport java.util.*; public class GeeksForGeeks { // Function to demonstrate pattern public static void printPattern(int n) { int i, j; // outer loop to handle rows for (i = n; i >= 1; i--) { // inner loop to handle columns for (j = 1; j <= i; j++) { System.out.print("*"); } // printing new line for each row System.out.println(); } // outer loop to handle rows for (i = 2; i <= n; i++) { // inner loop to handle columns for (j = 1; j <= i; j++) { System.out.print("*"); } // printing new line for each row System.out.println(); } } // Driver Function public static void main(String args[]) { int n = 6; printPattern(n); }} |
Output
****** ***** **** *** ** * ** *** **** ***** ******
