Rotating Number Pattern in Java

Beginner
⏱️ 6 min read
📚 Updated: Aug 2025
🎯 2 Code Examples
Nested Loops
Rotating number pattern output (12345, 23451, 34521, 45321, 54321) in Java programming

What You’ll Learn

How to print a rotating number pattern in Java:

12345, then 23451, then 34521, and so on.

Each row is built by printing numbers from i to rows, then appending the values from i-1 down to 1.

⭐ Pattern Output

For rows = 5, the pattern looks like this:

Output
12345
23451
34521
45321
54321
1

Complete Java Program

Use one loop to print i..rows, then another loop to print i-1..1.

Java
public class Main {
    public static void main(String[] args) {
        int rows = 5;

        for (int i = 1; i <= rows; i++) {
            for (int j = i; j <= rows; j++) {
                System.out.print(j);
            }
            for (int k = i; k > 1; k--) {
                System.out.print(k - 1);
            }
            System.out.println();
        }
    }
}

🧠 How It Works

1

Set the size

rows = 5 defines the largest printed digit.

Setup
2

Outer loop chooses the row start

Row i starts printing at i and shifts left each line.

Row control
3

Print the increasing run (i..rows)

for (j = i; j <= rows; j++) prints the increasing part like 2345.

Part 1
4

Append the decreasing run (i-1..1)

for (k = i; k > 1; k--) appends digits like 1 or 21.

Part 2
=

Rotating rows

Each row prints exactly rows digits, and the overall runtime grows like O(n²).

2

Variation — User Input Version

Let the user choose the maximum digit using Scanner:

Java
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        System.out.print("Enter the maximum number: ");
        int rows = sc.nextInt();

        for (int i = 1; i <= rows; i++) {
            for (int j = i; j <= rows; j++) {
                System.out.print(j);
            }
            for (int k = i; k > 1; k--) {
                System.out.print(k - 1);
            }
            System.out.println();
        }

        sc.close();
    }
}

💡 Tips for Enhancement

Try These

  • Print spaces between digits for readability (use System.out.print(j + " "))
  • Store each row in a StringBuilder to add separators easily
  • Change the second loop to append rows..(i+1) for a different rotation style
  • Use multi-digit formatting (%2d / %3d) when rows can be > 9
  • Try the same logic with characters (A..E) for an alphabet rotation

Avoid

  • Hard-coding 5 instead of using rows
  • Mixing loop variables (keep i for rows, j/k for columns)
  • Forgetting the newline after each row
  • Assuming single digits when rows can exceed 9

Key Takeaways

1

Each row is built from two parts: i..rows then i-1..1.

2

Every row prints exactly rows digits.

3

The second loop appends the wrap-around tail (like the ending 1 in 23451).

4

Overall work grows like O(n²) for n rows.

❓ Frequently Asked Questions

When i=5, the increasing part is just 5, and the second loop appends 4 3 2 1 (without spaces), giving 54321.
Yes. Print j + " " and (k-1) + " " in the loops, or build an array of values and join(" ").
It works, but without separators the output becomes hard to read. Use spaces and fixed-width formatting when printing multi-digit numbers.
O(n²) because for each row you print up to n values, and there are n rows.

Explore More Java Number Patterns!

Rotation-style patterns are great practice for combining an increasing run and a wrap-around tail.

All Number Patterns →
Did you know?

Many “rotation” patterns can be built by printing a main sequence first, then appending a second sequence that wraps back to the beginning.

About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
  • Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

AWS Certified Developer – Associate (Credly)

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