make cartesian coordinate with for-loop in php

i’m trying to make cartesian coordinate for my coursework and can only get here, I’m grateful if anyone can help me to fix this "0" line

<?php
$n=10;
for($i=-10;$i<=$n;$i++){
    for($j=-10;$j<=$n;$j++){
        if($i==0 || $j==0){
            echo " $i ";
        }   else {
                echo "   ";
            }
        
    }
    echo "\n";
}

Current output
What i expected

>Solution :

You can try this in mode console.
But it’s not really readable

But the principle is there

$n=10;

for($y=$n;$y>-$n;$y--)
{
    for($x=-$n;$x<=$n;$x++)
    {
        $infoDisplay = "  ";

        if($x==0)   $infoDisplay = $y;
        if($y==0)   $infoDisplay = $x;

        echo $infoDisplay;
    }

    echo "\n";
}