Reverse Alphabet, Diagonal * in PHP

Beginner
⏱️ 6 min read
📚 Updated: Aug 2025
🎯 2 Code Examples
Nested loops
Reverse alphabet pattern EDCBA with one diagonal star in PHP programming

What You'll Learn

Each row prints the reverse alphabet sequence (EDCBA) but swaps one position with *. The star shifts one column each row, creating a diagonal.

⭐ Pattern Output

Output
EDCB*
EDC*A
ED*BA
E*CBA
*DCBA
1

Complete PHP Program (A–E)

Fixed version (5 rows):

PHP
<?php
$alpha = range('A', 'Z');

$rows = 5;      // A..E
$end = $rows - 1;

for ($i = 0; $i < $rows; $i++) {
    for ($j = $end; $j >= 0; $j--) {
        if ($j === $i) {
            echo '*';
        } else {
            echo $alpha[$j];
        }
    }
    echo PHP_EOL;
}

🧠 How It Works

1

Outer loop controls the row

$i runs from 0 to $rows-1. This value is used to decide where the star appears on that row.

2

Inner loop prints reverse letters

$j counts down from $end to 0, so the default output per row is EDCBA.

3

Swap one position with *

When $j === $i, the current cell becomes *. That creates a diagonal line of stars across the square.

4

Print the line break

After building one row, print PHP_EOL to move to the next line. This keeps the output readable in CLI output.

Newline
=

Put it together

The outer loop controls rows, the inner loops control what prints on each row, and PHP_EOL separates the lines.

2

Variation — User Input (CLI) Version

Reads rows from stdin and clamps to 26 (A–Z):

PHP
<?php
echo "Enter the number of rows (max 26): ";
$rows = (int) trim(fgets(STDIN));
$rows = max(1, min($rows, 26));

$alpha = range('A', 'Z');
$end = $rows - 1;

for ($i = 0; $i < $rows; $i++) {
    for ($j = $end; $j >= 0; $j--) {
        if ($j === $i) {
            echo '*';
        } else {
            echo $alpha[$j];
        }
    }
    echo PHP_EOL;
}

❓ Frequently Asked Questions

It creates an array of uppercase letters so you can print alphabets using simple numeric indexes (0 for A, 1 for B, ...).
PHP_EOL is correct for CLI output and keeps examples consistent for terminal execution. In HTML, you would use <br> instead.
Most pattern programs print O(n) characters per row for n rows, so they are typically O(n2).

Next: PHP Alphabet Pattern 18

Continue to the next program for another alphabet pattern in PHP.

Program 18 →

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)

10 people found this page helpful

PHP Alphabet Pattern 16 PHP Alphabet Pattern 18