php数组计数父/子

Question

I can't get it working right. What i want is that counter will count every parent and inside parent child that will look like table of content, result needs to be:

<ul>
  <li><span style="color: red;">1</span>  <strong>a</strong>
  </li>
  <ul>
    <li><span style="color: red;">1.1</span>  <strong>b</strong>
    </li>
    <li><span style="color: red;">1.2</span>  <strong>c</strong>
    </li>
  </ul>
  <li><span style="color: red;">2</span>  <strong>e</strong>
  </li>
  <ul>
    <li><span style="color: red;">2.1</span>  <strong>f</strong>
    </li>
    <li><span style="color: red;">2.2</span>  <strong>g</strong>
    </li>
  </ul>
  <li><span style="color: red;">3</span>  <strong>h</strong>
  </li>
  <ul>
    <li><span style="color: red;">3.1</span>  <strong>k</strong>
    </li>
    <li><span style="color: red;">3.2</span>  <strong>l</strong>
    </li>
    <ul>
      <li><span style="color: red;">3.2.1</span>  <strong>m</strong>
      </li>
      <li><span style="color: red;">3.2.2</span>  <strong>n</strong>
      </li>
    </ul>
  </ul>
</ul>

There are n childs soo deep is unlimited.. My current code is here:

<?php 
$arr = array(
    array('id' => 1, 'title' => 'a', 'parent' => 0),
    array('id' => 2, 'title' => 'b', 'parent' => 1),
    array('id' => 3, 'title' => 'c', 'parent' => 1), 
    array('id' => 5, 'title' => 'e', 'parent' => 0),
    array('id' => 6, 'title' => 'f', 'parent' => 5),
    array('id' => 7, 'title' => 'g', 'parent' => 5), 
    array('id' => 8, 'title' => 'h', 'parent' => 0),
    array('id' => 9, 'title' => 'k', 'parent' => 8),
    array('id' => 10, 'title' => 'l', 'parent' => 8), 
    array('id' => 11, 'title' => 'm', 'parent' => 10), 
    array('id' => 12, 'title' => 'n', 'parent' => 10), 
);

function checkChilds($arr, $id){
    foreach ($arr as $key => $value) {
        if ($value['parent'] == $id) {
            return true;
        }
    }
    return false;
}

function getList($arr, $parent = 0, $subcounter = 1){
    $output = null;

    $output .= '<ul>';
    $counterParent = 1;
    $countChild = 1;
    foreach($arr as $key => $value) {
        if($value['parent'] == $parent){

            $counter = ($value['parent'] == 0) ? "{$counterParent}" : "{$subcounter}.{$countChild}";
            $output .= "<li><span style='color: red;'>{$counter}</span> <strong>{$value['title']}</strong></li>";

            if (checkChilds($arr, $value['id'])){
                $output .= getList($arr, $value['id'], $counterParent);
                $countChild++;
            }

            // counter for parent
            if($value['parent'] == 0) {
                $counterParent++;
            }
        }
    }
    $output .= '</ul>';

    return $output;
}

echo getList($arr);

</div>

Answer 1

Try this:

<?php 
$arr = array(
    array('id' => 1, 'title' => 'a', 'parent' => 0),
    array('id' => 2, 'title' => 'b', 'parent' => 1),
    array('id' => 3, 'title' => 'c', 'parent' => 1), 
    array('id' => 5, 'title' => 'e', 'parent' => 0),
    array('id' => 6, 'title' => 'f', 'parent' => 5),
    array('id' => 7, 'title' => 'g', 'parent' => 5), 
    array('id' => 8, 'title' => 'h', 'parent' => 0),
    array('id' => 9, 'title' => 'k', 'parent' => 8),
    array('id' => 10, 'title' => 'l', 'parent' => 8), 
    array('id' => 11, 'title' => 'm', 'parent' => 10), 
    array('id' => 12, 'title' => 'n', 'parent' => 10), 
);

function checkChilds($arr, $id){
    foreach ($arr as $key => $value) {
        if ($value['parent'] == $id) {
            return true;
        }
    }
    return false;
}

function getList($arr, $parent = 0, $subcounter = 1){
    $output = null;

    $output .= '<ul>';
    $counterParent = 1;
    $countChild = 1;
    foreach($arr as $key => $value) {
        if($value['parent'] == $parent){

            $counter = ($value['parent'] == 0) ? "{$counterParent}" : "{$subcounter}.{$countChild}";
            $output .= "<li><span style='color: red;'>{$counter}</span> <strong>{$value['title']}</strong></li>";

            if (checkChilds($arr, $value['id'])){
                $output .= getList($arr, $value['id'], $counter);
            }
            $countChild++;
            // counter for parent
            if($value['parent'] == 0) {
                $counterParent++;
            }
        }
    }
    $output .= '</ul>';

    return $output;
}

echo getList($arr);

You didn't pass the getList function all the prefix numbers, only the immediate parent. And you have to increase the counter always, not only if a new getList call is necessary.