Creating Pyramid in PHP - php

Question

I searched some code in php that creates the following output:
*
* *
* * *
* * * *
* * * * *
I noticed that there are lots of different approach they used to achieve this output. The other codes are long and the other is short. .
But there is one code that caught my attention. The code he used is too short and it's interesting for me, but I do not know how he do it because he did not left any explanation about it. The code is:
<pre><?php
$n = $i = 5;
while ($i--)
echo str_repeat(' ', $i).str_repeat('* ', $n - $i)."\n";
?></pre>
I do not know how the code works. I think the $n =$i = 5 is for the loop? Am I right? Is there anyone here can explain to me how the code works with simulation.
I found this code at Pyramid of asterisks in php
Any answers are welcome and much appreciated. Thank you guys!

Answer 1

Your code:
DEMO
<?php
$n = $i = 5;
while ($i--)
echo str_repeat(' ', $i).str_repeat('* ', $n - $i)."\n";
Loop 1:
$i = 5 (true) and decrement $i by 1, now $i = 4
str_repeat(' ', $i), means print empty space 4 times
then print '* ' $n - $i (5 - 4 = 1) time
Present output:
*
Loop 2:
$i = 4 (true) and decrement $i by 1, now $i = 3
str_repeat(' ', $i), means print empty space 3 times
then print '* ' $n - $i (5 - 3 = 2) times
Present output:
*
* *
Loop 3:
$i = 3 (true) and decrement $i by 1, now $i = 2
str_repeat(' ', $i), means print empty space 2 times
then print '* ' $n - $i (5 - 2 = 3) times
Present output:
*
* *
* * *
Loop 4:
$i = 2 (true) and decrement $i by 1, now $i = 1
str_repeat(' ', $i), means print empty space 1 times
then print '* ' $n - $i (5 - 1 = 4) times
Present output:
*
* *
* * *
* * * *
Loop 5:
$i = 1 (true) and decrement $i by 0, now $i = 0
str_repeat(' ', $i), means print empty space 0 times
then print '* ' $n - $i (5 - 0 = 5) times
Present output:
*
* *
* * *
* * * *
* * * * *
Loop 6:
$i = 0 (false) and loop breaks