Pattern programs are among the most common coding-round questions in campus and entry-level interviews. They look simple, but they test whether you can control nested loops, track rows and columns, and reason about conditions. This guide collects every pattern program on CodersBugs in one place: star, number, character and alphabet patterns, each with the expected output and a complete Java program.
Use the table of contents to jump to a section. If you are new to patterns, read the short method below first, then try to write each program yourself before you look at the code.
Table of contents
- How to solve any pattern program
- Star patterns
- Star patterns using the i + j trick
- Number patterns
- Character patterns
- Alphabet patterns A to Z
- Popular interview patterns
- FAQ
How to solve any pattern program
- Count the rows and columns. The outer loop (
i) handles rows and the inner loop (j) handles columns. - Decide what each position prints: a star, a number, a letter, or a space.
- Find the rule. Compare each cell with
i + j(the same value along an anti-diagonal) andj - i(the same value along a diagonal) to draw straight edges. - Print a new line after each row with
System.out.println(). - Dry run the first and last rows to check your condition.
Star patterns
Star patterns are the best place to start. Each program below prints the output shown above its code.
Star Pattern 1
Output:
***** ***** ***** ***** *****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
System.out.print("*");
}
System.out.println();
}
}
}Star Pattern 2
Output:
***** **** *** ** *
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j+i<=4)
System.out.print("*");
}
System.out.println();
}
}
}Star Pattern 3
Output:
* ** *** **** *****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0)
System.out.print("*");
}
System.out.println();
}
}
}Star Pattern 4
Output:
* ** *** **** ***** **** *** ** *
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0 && j+i<=8)
System.out.print("*");
}
System.out.println();
}
}
}Star Pattern 5
Output:
***** **** *** ** * ** *** **** *****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=-4 || j+i<=4)
System.out.print("*");
}
System.out.println();
}
}
}Star Pattern 6
Output:
* ** *** **** *****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j+i>=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 7
Output:
*****
****
***
**
*
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i>=0)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 8
Output:
*
**
***
****
*****
****
***
**
*
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i>=-4 && j+i>=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 9
Output:
* * * * * * * * * * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j+i>=4)
System.out.print("* ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 10
Output:
* *** ***** ******* *********
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 9; j++) {
if(j+i>=4 && j-i<=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 11
Output:
* * * * *
* * * *
* * *
* *
*
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i>=0)
System.out.print("* ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 12
Output:
*********
*******
*****
***
*
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 9; j++) {
if(j-i>=0 && j+i<=8)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 13
Output:
* * * * *
* * * *
* * *
* *
*
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i>=0)
System.out.print("* ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 14
Output:
*****
****
***
**
*
**
***
****
*****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i>=0 || j+i>=8)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 15
Output:
*****
****
***
**
*
**
***
****
*****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if((j-i>=0 && j<=4) || ( j-i<=0 && j>=4))
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 16
Output:
*********
*******
*****
***
*
***
*****
*******
*********
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j+i>=8 && j-i<=0 || j+i<=8 && j-i>=0)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 17
Output:
* * * * *
* * * *
* * *
* *
*
* *
* * *
* * * *
* * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j+i>=8 || j-i>=0)
System.out.print("* ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 18
Output:
*
* *
* * *
* * * *
* * * * *
* * * *
* * *
* *
*
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i>=-4 && j+i>=4)
System.out.print("* ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 19
Output:
*
***
*****
*******
*********
*******
*****
***
*
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j-i>=-4 && j+i<=12 && j+i>=4 && j-i<=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 20
Output:
********* **** **** *** *** ** ** * * ** ** *** *** **** **** *********
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j-i<=-4 || j+i<=4 || j+i>=12 || j-i>=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 21
Output:
***** ***** ***** ***** *****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j+i>=8 && j+i<=12 && i>=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 22
Output:
*****
*****
*****
*****
******
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j-i>=0 && j-i<=4 && i<=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 23
Output:
*****
*****
*****
*****
*****
*****
*****
*****
*****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j+i>=8 && j+i<=12 && i>=4 || j-i>=0 && j-i<=4 && i<=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star Pattern 24
Output:
*****
*****
*****
*****
*****
*****
*****
*****
*****
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j+i>=4 && j+i<=8 && i<=4 || j-i>=-4 && j-i<=0 && i>=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Star patterns using the i + j trick
These programs use a single condition on i + j and j - i instead of separate loops for spaces and stars. It is a quick way to draw triangles, pyramids and hourglass shapes.
Java Program to Print a Square Star Pattern (5×5)
Output:
***** ***** ***** ***** *****
Java code:
public class pattern {
public static void main(String[] args) {
for (int i = 0; i <5; i++) {
for (int j = 0; j < 5; j++) {
System.out.print("*");
}
System.out.println();
}
}
}Java Program to Print a Right Triangle Star Pattern
Output:
* ** *** **** *****
Java code:
public class Pattern {
public static void main(String[] args) {
for (int i = 0; i <5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i <=0)
{
System.out.print("*");
}
}
System.out.println();
}
}
}Java Program to Print an Inverted Right Triangle Star Pattern
Output:
***** **** *** ** *
Java code:
public class pattern {
public static void main(String[] args) {
for (int i = 0; i <5; i++) {
for (int j = 0; j < 5; j++) {
if(i+j <= 4)
{
System.out.print("*");
}
}
System.out.println();
}
}
}Java Program to Print a Mirrored Right Triangle Star Pattern
Output:
* ** *** **** *****
Java code:
public class Pattern {
public static void main(String[] args) {
for (int i = 0; i <5; i++) {
for (int j = 0; j < 5; j++) {
if( i+j>=4) //
{
System.out.print("*");
}
else
{
System.out.print(" ");
}
}
System.out.println();
}
}
}Java Program to Print a Pyramid Star Pattern
Output:
* *** ***** ******* *********
Java code:
public class Pattern {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 9; j++) {
if(i+j>=4 && j-i<=4)
{
System.out.print("*");
}
else
{
System.out.print(" ");
}
}
System.out.println();
}
}
}Java Program to Print an Inverted Pyramid Star Pattern
Output:
*********
*******
*****
***
*
Java code:
public class Pattern {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 9; j++) {
if(j-i >=0 && i+j <=8)
{
System.out.print("*");
}
else
{
System.out.print(" ");
}
}
System.out.println();
}
}
}Java Program to Print a Right-Aligned Triangle with Spaced Stars
Output:
* * * * * * * * * * * * * * *
Java code:
public class Pattern {
public static void main(String[] args) {
for (int i = 0; i <5; i++) {
for (int j = 0; j < 5; j++) {
if(i+j >=4)//i+j==4 || j-i==4 i+j==4 || j-i==4
{
System.out.print("* ");
}
else
{
System.out.print(" ");
}
}
System.out.println();
}
}
}Java Program to Print a Sideways Hourglass Star Pattern
Output:
***** **** *** ** * ** *** **** *****
Java code:
public class Pattern {
public static void main(String[] args) {
for (int i = 0; i <9; i++) {
for (int j = 0; j < 5; j++) {
if( j-i<=-4 || i+j<=4) //
{
System.out.print("*");
}
else
{
System.out.print(" ");
}
}
System.out.println();
}
}
}Java Program to Print a Left-Pointing Triangle (Half Diamond) Star Pattern
Output:
*
**
***
****
*****
****
***
**
*
Java code:
public class Pattern {
public static void main(String[] args) {
for (int i = 0; i <9; i++) {
for (int j = 0; j < 5; j++) {
if( i+j>=4 && j-i>-5) //
{
System.out.print("*");
}
else
{
System.out.print(" ");
}
}
System.out.println();
}
}
}Java Program to Print a Right-Aligned Sideways Hourglass Star Pattern
Output:
* * * * *
* * * *
* * *
* *
*
* *
* * *
* * * *
* * * * *
Java code:
public class Pattern {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(i+j >=8 || j-i >=0 )
{
System.out.print("* ");
}
else
{
System.out.print(" ");
}
}
System.out.println();
}
}
}Number patterns
Number patterns are asked very often in interviews. The rule usually depends on the row number, the column number, or a counter that keeps increasing.
Number Pattern 1
Output:
1 12 123 1234 12345
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0)
System.out.print(j+1);//in vertical line take j+1 equation
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 2
Output:
5 54 543 5432 54321
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0)
System.out.print(5-j);//in vertical line take j+1 equation
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 3
Output:
12345 2345 345 45 5
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j+i<=4)
System.out.print(j+i+1);
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 4
Output:
1 2 3 4 5
2 3 4 5
3 4 5
4 5
5
5
4 5
3 4 5
2 3 4 5
1 2 3 4 5
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 5; j++) {
if(j-i>=0 || j+i>=9)
System.out.print(j+1+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 5
Output:
5 4 5 3 4 5 2 3 4 5 1 2 3 4 5
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j+i>=4)
System.out.print(j+1+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 6
Output:
1 2 2 3 3 3 4 4 4 4 5 5 5 5 5
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j+i>=4)
System.out.print(i+1+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 7
Output:
1 12 123 1234 12345 123456 1234567 12345678 123456789
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j-i<=0)
System.out.print(j+1);
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 8
Output:
1 22 333 4444 55555 666666 7777777 88888888 999999999
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j-i<=0)
System.out.print(i+1);
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 9
Output:
9 98 987 9876 98765 987654 9876543 98765432 987654321
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j-i<=0)
System.out.print(9-j);
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 10
Output:
9 88 777 6666 55555 444444 3333333 22222222 111111111
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j-i<=0)
System.out.print(9-i);
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 11
Output:
000111222333444555666777888999 000111222333444555666777888999 000111222333444555666777888999 000111222333444555666777888999 000111222333444555666777888999 000111222333444555666777888999 000111222333444555666777888999 000111222333444555666777888999
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 8; i++) {
for (int j = 0; j < 30; j++) {
System.out.print(j/3);
}
System.out.println();
}
}
}Number Pattern 12
Output:
1
2 2
3 3 3
4 4 4 4
5 5 5 5 5
4 4 4 4
3 3 3
2 2
1
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(i<=4 && j+i>=4)
System.out.print(i+1+" ");//
else if(i>=5 && j-i>=-4)
System.out.print(9-i+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 13
Output:
1
2 2
3 3 3
4 4 4 4
5 5 5 5 5
6 6 6 6 6 6
7 7 7 7 7 7 7
8 8 8 8 8 8 8 8
9 9 9 9 9 9 9 9 9
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j+i>=8)
System.out.print(i+1+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 14
Output:
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5
1 2 3 4 5 6
1 2 3 4 5 6 7
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8 9
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j+i>=8)
System.out.print((j+i)-7+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 15
Output:
9 9 9 9 9 9 9 9 9
8 8 8 8 8 8 8 8
7 7 7 7 7 7 7
6 6 6 6 6 6
5 5 5 5 5
4 4 4 4
3 3 3
2 2
1
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
if(j-i>=0)
System.out.print(9-i+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 16
Output:
1 12 123 1234 12345 1234 123 12 1
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0 && j+i<=8)
System.out.print(j+1);
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 17
Output:
1 1 2 1 2 3 1 2 3 4 1 2 3 4 5
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j+i>=4)
System.out.print((j+i)-3+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 18
Output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Java code:
public class MainClass {
public static void main(String[] args) {
int count =1;
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0 )
System.out.print(count+++ " ");//
else
System.out.print("");
}
System.out.println();
}
}
}Number Pattern 19
Output:
12345 1234 123 12 1 12 123 1234 12345
Java code:
public class MainClass {
public static void main(String[] args) {
int count =1;
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=-4 || j+i<=4)
System.out.print(j+1);//
else
System.out.print("");
}
System.out.println();
}
}
}Number Pattern 20
Output:
1 2 3 4 5
2 3 4 5
3 4 5
4 5
5
4 5
3 4 5
2 3 4 5
1 2 3 4 5
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if((j+i>=8))
System.out.print((j+1)+" ");
else if(j-i>=0)
System.out.print((j+1)+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 21
Output:
12345
1234
123
12
5
45
345
2345
12345
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if((j+i>=8))
System.out.print(j+1);
else if(j-i>=0)
System.out.print((j-i)+1);
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 22
Output:
1 121 12321 1234321 123454321
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i=i+2) {
int num=1;
for (int j = 0; j < 9; j++) {
if(j-i<=0)
System.out.print(num);
if(2*j-i<0)
num++;
else
num--;
}
System.out.println();
}
}
}Number Pattern 23
Output:
1 121 12321 1234321 123454321
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
int num=1;
for (int j = 0; j < 9; j++) {
if(j+i>=4 && j-i<=4){
System.out.print(num);
if(j<4)
num++;
else
num--;
}
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 24
Output:
1 2 6 9 3 7 10 12 13
Java code:
public class MainClass {
public static void main(String[] args) {
int num=1;
for (int i = 0; i < 5; i=i+2) {
int num2=num;
int diff=4;
for (int j = 0; j < 5; j++) {
if(j-i<=0)
{
System.out.print(num2+" ");
num2=num2+diff;
diff--;
}
}
System.out.println();
num++;
}
}
}Number Pattern 25
Output:
1 1 12 21 123 321 1234 4321 1234554321
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 10; j++) {
if(j-i<=0)
System.out.print(j+1);
else if(j+i>=9)
System.out.print(10-j);
else
System.out.print(" ");
}
System.out.println();
}
}
}Number Pattern 26
Output:
00*00 00*00 ***** 00*00 00*00
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j==2 || i==2)
System.out.print("*");//
else
System.out.print("0");
}
System.out.println();
}
}
}Character patterns
Character patterns work like number patterns, but you print letters instead of digits.
Character Pattern 1
Output:
A AB ABC ABCD ABCDE
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0)
System.out.print((char)(j+65));
}
System.out.println();
}
}
}Character Pattern 2
Output:
A BB CCC DDDD EEEEE
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 5; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0)
System.out.print((char) (i+65));
}
System.out.println();
}
}
}Character Pattern 3
Output:
A BB CCC DDDD EEEEE DDDD CCC BB A
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j+i<=8 && i>=4)
System.out.print((char)(8-i+65));
else if(j-i<=0 && i<=4)
System.out.print((char)(i+65));
else
System.out.print("");
}
System.out.println();
}
}
}Character Pattern 4
Output:
A AB ABC ABCD ABCDE ABCD ABC AB A
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0 && j+i<=8 )
System.out.print((char)(j+65));
else
System.out.print("");
}
System.out.println();
}
}
}Character Pattern 5
Output:
ABCDEF ABCDE ABCD ABC AB A A AB ABC ABCD ABCDE ABCDEF
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 12; i++) {
for (int j = 0; j < 6; j++) {
if(j-i<=-6 || j+i<=5 )
System.out.print((char)(j+65));
else
System.out.print("");
}
System.out.println();
}
}
}Character Pattern 6
Output:
FEDCBA EDCBA DCBA CBA BA A A BA CBA DCBA EDCBA FEDCBA
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 12; i++) {
for (int j = 0; j < 6; j++) {
if(j-i<=-6)
System.out.print((char)(i-j-6+65));
else if(j+i<=5)
System.out.print((char)(5-(j+i)+65));
else
System.out.print("");
}
System.out.println();
}
}
}Character Pattern 7
Output:
A
A B
A B C
A B C D
A B C D E
A B C D E F
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 6; i++) {
for (int j = 0; j < 6; j++) {
if(j+i>=5)
System.out.print((char)((j+i)-5+65)+" ");
else
System.out.print(" ");
}
System.out.println();
}
}
}Character Pattern 8
Output:
FEDCBA EDCBA DCBA CBA BA A
Java code:
public class MainClass {
public static void main(String[] args) {
char a ='F';
for (int i = 0; i < 6; i++) {
for (int j = 0; j < 6; j++) {
if(i+j<6)
System.out.print((char)(a-j-i ));
else
System.out.print(" ");
}
System.out.println();
}
}
}Character Pattern 9
Output:
F FE FED FEDC FEDCB FEDCBA
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 6; i++) {
for (int j = 0; j < 6; j++) {
if(j-i<=0)
System.out.print((char)(5-j +65));
else
System.out.print(" ");
}
System.out.println();
}
}
}Character Pattern 10
Output:
ABCDEF ABCDE ABCD ABC AB A
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 6; i++) {
for (int j = 0; j < 6; j++) {
if(j+i<=5)
System.out.print((char)(j+65));
else
System.out.print(" ");
}
System.out.println();
}
}
}Character Pattern 11
Output:
A BC DEF GHIJ KLMNO PQRSTU
Java code:
public class MainClass {
public static void main(String[] args) {
int count=0;
for (int i = 0; i < 6; i++) {
for (int j = 0; j < 6; j++) {
if(j-i<=0)
System.out.print((char)(count++ +65));
else
System.out.print(" ");
}
System.out.println();
}
}
}Character Pattern 12
Output:
A BA CBA DCBA EDCBA FEDCBA
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 6; i++) {
for (int j = 0; j < 6; j++) {
if(j-i<=0)
System.out.print((char)(+i-j+65));
else
System.out.print(" ");
}
System.out.println();
}
}
}Character Pattern 13
Output:
A BG CHM DINS EJOTY FKPUZ_
Java code:
public class MainClass {
public static void main(String[] args) {
int num=0;
for (int i = 0; i < 6; i++) {
int num2=num;
int def=5;
for (int j = 0; j < 6; j++) {
if(j-i<=0) {
System.out.print((char)(num2+65));
num2= num2+def;
}
}
System.out.println();
num++;
}
}
}Character Pattern 14
Output:
A AB ABC ABCD ABCDE ABCD ABC AB A
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 5; j++) {
if(j-i<=0 && j+i<=8 )
System.out.print((char)(j+65));
else
System.out.print("");
}
System.out.println();
}
}
}Character Pattern 15
Output:
ABCDEF ABCDE ABCD ABC AB A A AB ABC ABCD ABCDE ABCDEF
Java code:
public class MainClass {
public static void main(String[] args) {
for (int i = 0; i < 12; i++) {
for (int j = 0; j < 6; j++) {
if(j-i<=-6 || j+i<=5 )
System.out.print((char)(j+65));
else
System.out.print("");
}
System.out.println();
}
}
}Alphabet patterns A to Z
These programs draw each letter of the English alphabet using stars.
Print the letter A in Java
Output:
*** * * * * ***** * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 && i!=0 || j==4 && i!=0 || i==0 && j!=0 && j!=4 || i==3 )
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter B in Java
Output:
**** * * * * **** * * * * ****
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 || j==4 && i!=0 && i!=3 && i!=6|| i==0 && j!=4 || i==3 && j!=4 || i==6 && j!=4 )
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter C in Java
Output:
**** * * * * ****
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 && i!=0 && i!=5 || i==0 && j!=0 || i==5 && j!=0)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter D in Java
Output:
**** * * * * * * * * * * ****
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 || i==0 && j!=4 || j==4 && i!=0 && i!=6 || i==6 && j!=4 )
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter E in Java
Output:
***** * * ***** * * *****
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 || i==0 || i==3 || i==6)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter F in Java
Output:
***** * * ***** * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 || i==0 || i==3)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter G in Java
Output:
***** * * * ** * * * * *****
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 || i==0 && j!=5 || i==6 && j!=5|| i==3 && j!=1 && j!=2 || j==4 && i!=1 && i!=2)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter H in Java
Output:
* * * * * * ***** * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 || i==3 || j==4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter I in Java
Output:
***** * * * * * *****
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==2 || i==0 || i==6)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter J in Java
Output:
***** * * * * * * ***
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==2 || i==0 || i==6 && j!=3 && j!=4 || i==5 && j!=3 && j!=4 && j!=1)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter K in Java
Output:
* * * * * * ** * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 || j+i==4 || j-i==-2)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter L in Java
Output:
* * * * * * *****
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 || i==6)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter M in Java
Output:
* * ** ** * * * * * * * * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<7;j++) {
if(j==0 || j-i==0 && i<=3 || j+i==6 && i<=3 || j==6)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter N in Java
Output:
* * ** * * * * * * * * * * * ** * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<7;j++) {
if(j==0 || j-i==0 || j==6)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter O in Java
Output:
*** * * * * * * * * * * ***
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 && i!=0 && i!=6 || i==0 && j!=4 && j!=0 || j==4 && i!=0 && i!=6 || i==6 && j!=4 && j!=0 )
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter P in Java
Output:
*** * * * * **** * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 && i!=0 || i==0 && j!=0 && j!=4 || j==4 && i!=0 && i<=2 || i==3 && j!=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter R in Java
Output:
*** * * * * **** * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 && i!=0 || i==0 && j!=0 && j!=4 || j==4 && i!=0 && i!=3 || i==3 && j!=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter S in Java
Output:
*****
*
*
*****
*
*
*****
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 && i<=3 || i==0 || i==3 || i==6 || j==4 && i>=4)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter T in Java
Output:
***** * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==2 || i==0)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter U in Java
Output:
* * * * * * * * * * * * ***
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<5;j++) {
if(j==0 && i!=6 || i==6 && j!=0 && j!=4 || j==4 && i!=6)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter V in Java
Output:
* *
* *
* *
* *
* *
* *
*
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<13;j++) {
if(j-i==0 || j+i==12 )
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter W in Java
Output:
* * * * * * * ** ** * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<4;i++) {
for(int j=0;j<7;j++) {
if(j==0 || j+i==3 || j-i==3 || j==6 )
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter X in Java
Output:
* * * * * * * * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<7;j++) {
if(j-i==0 || j+i==6)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter Y in Java
Output:
* * * * * * * * * *
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<7;j++) {
if(j-i==0 && i<=3|| j+i==6 && i<=3 || j==3 && i>=3)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Print the letter Z in Java
Output:
*******
*
*
*
*
*
*******
Java code:
public class MainClass {
public static void main(String[] args) {
for(int i=0;i<7;i++) {
for(int j=0;j<7;j++) {
if(i==0 || j+i==6 || i==6)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println();
}
}
}Popular interview patterns
A mixed set of patterns that are often asked in coding rounds.
Interview Pattern 1
Output:
1 1 1 2 1 2 3 1 2 3 1 2 3 4 1 2 3 4 5 1 2 3 4 5
Java code:
import java.util.*;
public class Main {
public static void main(String[] args) {
int i, j, number, n = 6;
for (i = 1; i < n; i++) {
number = 1;
if (i % 2 == 1) {
for (j = 1; j <= i; j++) {
System.out.print(j + " ");
number++;
}
System.out.println();
}
for (j = 1; j <= i; j++) {
System.out.print(j + " ");
number++;
}
System.out.println();
}
}
}Interview Pattern 2
Output:
1 2 3 4 5 1 2 3 4 5 1 2 3 4 1 2 3 1 2 3 1 2 1 1
Java code:
import java.util.*;
public class Main {
public static void main(String[] args) {
int i, j, number, n = 6;
for (i = 5; i >= 1; i--) {
number = 1;
if (i % 2 == 1) {
for (j = 1; j <= i; j++) {
System.out.print(j + " ");
number++;
}
System.out.println();
}
for (j = 1; j <= i; j++) {
System.out.print(j + " ");
number++;
}
System.out.println();
}
}
}Interview Pattern 3
Output:
0 10 010 1010 01010
Java code:
import java.util.*;
public class Main {
public static void main(String[] args) {
for (int i = 0; i <= 5; i++) {
for (int j = 0; j <= 5; j++) {
if(j-i<0){
if((j+i)%2==0) {
System.out.print("1");
} else {
System.out.print("0");
}
}
else
System.out.print(" ");
}
System.out.println();
}
}
}Interview Pattern 4
Output:
5 4 3 2 1 5 4 3 2 5 4 3 5 4 5
Java code:
import java.util.*;
public class Main {
public static void main(String[] args) {
for (int i = 1; i <=5; i++) {
{
for (int j = 5; j >=i; j--) {
System.out.print(j + " ");
}
System.out.println();
}
}
}
}Interview Pattern 5
Output:
1 1 0 1 2 3 1 0 1 0 1 2 3 4 5
Java code:
public class Main {
public static void main(String[] args) {
for (int i = 1; i <= 5; i++) {
{
for (int j = 1; j <= i; j++) {
if (i % 2 == 1) {
System.out.print(j + " ");
} else {
if (j % 2 == 1) {
System.out.print("1" + " ");
} else {
System.out.print("0" + " ");
}
}
}
System.out.println();
}
}
}
}Interview Pattern 6
Output:
10 9 9 8 8 8 7 7 7 7 6 6 6 6 6
Java code:
public class Main {
public static void main(String[] args) {
int num=10;
for(int i=1;i<=5;i++)
{
for(int j=1;j<=i;j++)
{
System.out.print(num+" ");
}
System.out.println();
num--;
}
}
}Interview Pattern 7
Output:
O P P Q Q Q R R R R S S S S S
Java code:
public class Main {
public static void main(String[] args) {
for (int i = 1; i <= 5; i++) {
String s = "O";
if (i > 1) {
s = String.valueOf((char)('P' + i - 2));
for (int j = 1; j < i; j++) {
s += s.charAt(0);
}
}
System.out.println(s);
}
}
}Interview Pattern 8
Output:
1# 2# 3# 4# 5# 6# 7# 8# 9# 10#
Java code:
import java.util.*;
public class Main {
public static void main(String[] args) {
int count =1;
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 54; j++) {
if(j-i<=0 )
System.out.print(count++ +"# ");//
else
System.out.print("");
}
System.out.println();
}
}
}FAQ
What is the easiest way to learn pattern programs?
Start with a square and a right triangle, then move to pyramids. Once you are comfortable, use the i + j and j - i conditions to draw diagonal edges.
Why do interviewers ask pattern programs?
They show how well you handle nested loops, conditions and dry runs, which are the basics of problem solving.
Can I write these in C++, Python or JavaScript?
Yes. The logic is the same in every language. Only the loop and print syntax change.
How should I practice?
Cover the code, look only at the output, and try to write the program yourself. Then compare your condition with the one given here.
