Shrinking Repeated Number Pattern in PHP

Beginner
⏱️ 5 min read
📚 Updated: Aug 2025
🎯 2 Code Examples
Nested Loops
Shrinking repeated number pattern output (11111, 2222, 333, 44, 5) in PHP programming

What You’ll Learn

How to print a shrinking repeated number pattern in PHP using nested for loops. Each row prints the same digit multiple times, but the repetition count decreases by 1 on each next row.

This pattern teaches you how to set the inner loop length using a variable start point.

⭐ Pattern Output

For $n = 5, the pattern looks like this:

Output
11111
2222
333
44
5
1

Complete PHP Program

Fixed $n = 5 version:

PHP
<?php
$n = 5;

for ($i = 1; $i <= $n; $i++) {
    for ($j = $i; $j <= $n; $j++) {
        echo $i;
    }
    echo PHP_EOL;
}

🧠 How It Works

1

Choose the size

$n = 5; defines how many rows to print and the maximum repetition count.

Setup
2

Outer loop (digit increases)

for ($i = 1; $i <= $n; $i++) selects which digit to print on the row.

Row control
3

Inner loop (repeat count shrinks)

for ($j = $i; $j <= $n; $j++) runs ($n - $i + 1) times, so the number repeats fewer times on each next row.

Repetition
4

New line

echo PHP_EOL; ends the row and moves to the next line.

Line break
=

Shrinking repeated pattern

The total printed digits are still triangular, so runtime is O(n²).

2

Variation — User Input (CLI) Version

Let the user decide $n at runtime (run from terminal with php):

PHP
<?php
echo "Enter the value of n: ";
$n = (int) trim(fgets(STDIN));

for ($i = 1; $i <= $n; $i++) {
    for ($j = $i; $j <= $n; $j++) {
        echo $i;
    }
    echo PHP_EOL;
}

💡 Tips for Enhancement

Try These

  • Validate input (reject $n < 1) before printing
  • Add spaces between digits (for example, echo $i . " ";)
  • Reverse the digit direction (count down) to create inverted variants
  • Print a constant digit (like 1) to build 11111, 1111, 111...
  • Try printing stars instead of digits for star patterns

Avoid

  • Forgetting the newline after each row
  • Using negative or zero values without validating input
  • Printing $j instead of $i (this pattern repeats the row digit)
  • Assuming CLI input is always valid (guard fgets() and casting if needed)

Key Takeaways

1

The outer loop selects the digit to print on each row.

2

The inner loop runs from $i to $n, controlling how many times the digit repeats.

3

Total printed digits are triangular, so runtime is O(n²).

4

This pattern is great practice for thinking in terms of “range length” ($n - $i + 1).

❓ Frequently Asked Questions

Because when $i = $n, the inner loop runs only once (from $j = $n to $n), so the digit prints once.
Set $n to the number of rows you want. The first row prints 1 repeated $n times, and the last row prints $n once.
Yes—print echo $i . " "; instead of echo $i;.
O(n²) for n rows: total prints are 1+2+…+n = n(n+1)/2.

Next: PHP Number Pattern 13

Continue to Program 13 to print an alternating ascending/descending pattern using an if condition.

Program 13 →
Did you know?

Patterns like this are a good way to learn how changing the inner loop start value changes the row length without needing extra variables.

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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