PHP - 以3为一组打印数组的值

I have an array; the following

$arr = array(
    '1', 
    '2',
    '3',
    '4',
    '5',
    '6',
    '7',
    '8',
    '9',
);

and I want to print something like

• 1
• 2
• 3

• 4
• 5
• 6

• 7
• 8
• 9

My code only print the first 3

for($m = 0; $m < 9; $m++){
echo "<ul>";

for($i = 0; $i <3; $i++){
    echo "<li>";
    echo $arr[$i];
    echo "</li>";
}

echo "</ul>";
}

Really appreciate it!

You can use php array_chunk($arr,number of chunk)

$arr = array( '1', '2', '3', '4', '5', '6', '7', '8', '9');
    $chunkArray = array_chunk($arr,3);

    foreach ($chunkArray as $key => $value) {
        echo '<ul>';
        foreach ($value as $key1 => $value1) {
            echo '<li>'.$value1.'</li>';
        }
        echo '</ul>';

    }

One option is to use modulo (%) like:

$arr = array(
    '1', 
    '2',
    '3',
    '4',
    '5',
    '6',
    '7',
    '8',
    '9',
);


$perGroup = 3;

for($m = 0; $m < count($arr); $m++){
    if ( $m % $perGroup === 0 ) echo "<ul>";

    echo "<li>";
    echo $arr[$m];
    echo "</li>";

    if ( $m % $perGroup === ( $perGroup - 1 ) || $m === (  count($arr) - 1 ) ) echo "</ul>";
}

This will result to:

<ul>
  <li>1</li>
  <li>2</li>
  <li>3</li>
</ul>
<ul>
  <li>4</li>
  <li>5</li>
  <li>6</li>
</ul>
<ul>
  <li>7</li>
  <li>8</li>
  <li>9</li>
</ul>

</div>

Try This

$arr = array(
        '1', 
        '2',
        '3',
        '4',
        '5',
        '6',
        '7',
        '8',
        '9',
    );
    $i=0;
    echo "<ul>";

    foreach($arr as $value)
    {
        if($i ==3)
        {
            echo "</ul><p></p><ul>";
            $i=0;  
        }

        echo "<li>";
        echo $value;
        echo "</li>";   

        $i++;
    }
    echo "</ul>";