How to achieve this number pattern with n input - php

Question

I want to give n as a input and get a pattern like this.
pattern If n = 4
1
222
33333
4444444
33333
222
1
What is the perfect way to achieve this?
I have tried. But my code is not good! Is there any way to do this with less and clear code!?
echo '<pre>';
$n=4;
for ($i=1; $i <= $n*2-1; $i++) {
if($n<$i){ //bottom part
$scount=$i-$n;
$iterator = 0;
while($iterator != $scount){
$iterator++;
echo ' ';
}
$num = ($n*2)-$i;
$loop = $num*2-1;
$iterator = 0;
while($iterator != $loop){
$iterator++;
echo $num;
}
}elseif ($n==$i){ // middle part
$loop = $i*2-1;
$iterator = 0;
while ($iterator != $loop) {
$iterator++;
echo $i;
}
}else{ //top part
$scount = $n-$i;
$iterator=0;
while ($iterator != $scount) {
$iterator++;
echo ' ';
}
$loop = $i*2-1;
$iterator = 0;
while($iterator != $loop){
$iterator++;
echo $i;
}
}
echo "<br>";
}
?>````

Answer 1

On a similar line to the other answers, but this builds a string with the output. This allows it to build each of the repeating lines in the loop and add it to the start and end of the result string. This means the loop is only run $n-1 times (plus the first line which sets the middle line)...
$n=4;
$output = str_repeat("$n", (2*$n)-1).PHP_EOL;
for ( $i = $n-1; $i>0; $i-- ) {
$line = str_repeat(' ', $n-$i).str_repeat("$i", (2*$i)-1);
$output = $line.PHP_EOL.$output.$line.PHP_EOL;
}
echo $output;

Answer 2

Two for loops which repeats the number of spaces needed and characters.
$n = 4;
for($i=1;$i<=$n;$i++){
echo str_repeat(" ", $n-$i+1) . str_repeat($i, $i*2-1) . "\n";
}
for($i=$n-1;$i>0;$i--){
echo str_repeat(" ", $n-$i+1) . str_repeat($i, $i*2-1) . "\n";
}
https://3v4l.org/1hK3s

Answer 3

You can solve this by noticing the longest line is the one with the max value of n, and that has 2*n-1 n's in it. All other lines need spacing to make them line up with that one which will be half the difference between the number of n's on that line and the number on the longest line. str_repeat is a good way of generating those repeated strings:
echo "<pre>\n";
$n=4;
$max_length = $n * 2 - 1;
for ($i = 1; $i <= $n * 2 - 1; $i++) {
$this_n = ($i <= $n) ? $i : $n * 2 - $i;
$num_ns = $this_n * 2 - 1;
echo str_repeat(' ', ($max_length - $num_ns) / 2);
echo str_repeat("$this_n", $num_ns);
echo "\n";
}
echo '</pre>';
Output:
<pre>
1
222
33333
4444444
33333
222
1
</pre>
Demo on 3v4l.org