使用PHP for循环创建星型模式

I'm trying to echo stars and zero like the pattern below

*
***0
******00
**********000

However I'm getting this result

    *
    **0
    ***00
    ****000
    *****0000
    ******00000

here is my code

for ($i=0; $i<=10; $i++)
{   
    echo "*";
    for ($j=0; $j<$i; $j++)
    {   
       echo "*";

    }
        for ($z=0; $z<$i; $z++)
            {
                echo "0";
            }       
    echo "</br>";    
} 
?>

The number of stars is indicated by triangle numbers, 1, 1+2, 1+2+3. You want to increment your inner loop max value by $i with every iteration:

$k = 0;
for ($i=1; $i<=10; $i++)
{
    $k += $i;
    for ($j=1; $j<=$k; $j++)
    {   
       echo "*";
    }
    ...
}

This is also a good case where your loops should be initialized with 1 rather than 0, because it is more intuitive. 0-based loops work best when you are working with arrays.

Smells like homework... But ok, what about this:

$star = "*";

echo $star."
";

    for ($i=0; $i<=10; $i++)
    {   
        $star = $star."**";
        echo $star;

        echo str_repeat("0", $i+1);

        echo "
";    
    } 

Outcome:

*
***0
*****00
*******000
*********0000
***********00000
*************000000
***************0000000
*****************00000000
*******************000000000
*********************0000000000
***********************00000000000

Demo:

http://sandbox.onlinephpfunctions.com/code/583644f782005adb9e018b965cbbdefaf63c7c79

I think something like this is more efficient; you can cache the current sequence of stars and zeros.

$cache_star = "";
$cache_zero = "";
for ($i=1; $i<=10; $i++)
{
    for ($j=1; $j<=$i; $j++)
    {   
       $cache_star .= "*";
    }
    echo $cache_star.$cache_zero;
    $cache_zero .= "0";
}

Here's what I got:

for($i = 1; $i != 5; $i++)
{
    $triangle = (0.5 * $i) * ($i + 1);
    echo str_repeat('*', $triangle) . str_repeat('0', $i) . PHP_EOL;
}

Uses the formula 0.5n(n + 1) - the triangle numbers formula.

Example output:

*0
***00
******000
**********0000