A PHP number pattern is a script that prints integers in rows. The outer for loop chooses the row. The inner for loop echos each number, then echo PHP_EOL ends that row.
echo does not add a newline, so single digits sit next to each other (123). Two calls with no separator glue wider values: echo 10; echo 11; prints 1011. The dot does the same, because 10 . 11 is the string "1011". 10 + 11 is addition, so that expression prints 21.
Echo $col for 1, 2, 3… Echo $row to repeat the same digit. A separate $value that you increment is how a running sequence crosses from one row to the next.
Count the outer loop down when the first row should be the longest. The inner loop still walks 1 through the current width.
<?php
for ($row = $rows; $row >= 1; $row--) {
for ($n = 1; $n <= $row; $n++)
echo $n; // digits, no space
echo PHP_EOL; // end the row
}Map each part of the console shape to a PHP value or call.
| Piece | PHP | What it does |
|---|---|---|
| Digit | echo $n | Writes the number and stays on the row |
| Same digit | echo $row | Repeats the row number on that line |
| Next value | $value++ | Keeps counting across columns and rows |
| Join | 10 . 11 | The string "1011" |
| Add | 10 + 11 | The number 21 |
| New row | echo PHP_EOL | Ends the row |
| Width | printf("%2d ", $n) | Two columns, then a space |
| Odd or even | $n % 2 | 0/1 patterns from the remainder |
| One digit | chr(ord('0') + $n) | One character for 0–9 |
Three scripts. Each one changes only the PHP that chooses the number or its width.
Start $row at 5 and stop at 1. The inner loop echoes 1 through $row.
<?php
$rows = 5;
for ($row = $rows; $row >= 1; $row--) {
for ($n = 1; $n <= $row; $n++) {
echo $n;
}
echo PHP_EOL;
}$row-- makes each later line one digit shorter.for always restarts at 1, so every row begins with 1.echo $n stays on the row. echo PHP_EOL starts the next one.The inner loop only decides how many times to echo. The value is $row.
<?php
$rows = 5;
for ($row = 1; $row <= $rows; $row++) {
for ($col = 1; $col <= $row; $col++) {
echo $row;
}
echo PHP_EOL;
}1.3 each time.echo $row for echo $col and the line becomes 123.printf("%2d ", $value) reserves two columns and adds the gap. PHP_EOL still ends the row.
<?php
$value = 1;
for ($row = 1; $row <= 4; $row++) {
for ($col = 1; $col <= $row; $col++) {
printf("%2d ", $value);
$value++;
}
echo PHP_EOL;
}$value lives outside both loops, so counting continues on the next row.%2d turns 1 into two columns and leaves 10 as two digits.echo PHP_EOL closes the row.Each card is a full PHP script: nested for loops, a number for the cell, and echo. Open one for the walkthrough.
A full PHP walkthrough of the descending number triangle, from echo $n through echo PHP_EOL.
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