使用array_map（）函数后获取数组字

Question

我的代码低于一切，但是我在结果末尾得到了多余的单词“ array”

$headings = ['heading one', 'heading two', 'heading three'];
$features_list = ['feature1', 'feature2', 'feature3'];

$content = array_map(null, $headings, $features_list);

使用类似的数组映射并使用以下代码解决结果

foreach ($content as $entry) { ?>
<tr>
   <td>
       <?php  printf('<p><strong>%s</strong></p>', $entry[0]); ?>
        </td>
         <td>
          <p class="xp-options">
          <?php
          if ($entry[1][2] == 1) {
             echo '<i class="fa fa-check-circle"></i>';
             } else {
             echo '<i class="fa fa-times-circle"></i>';
             }
         ?>
          <?php printf($entry[1][0]); ?>

          <?php if (!empty($entry[1][1])):?>
          <a href="#" data-toggle="tooltip" title="<?php echo $entry[1][1] ?>"><i class="fa fa-question-circle"></i></a>
          <?php endif; ?>
        </p>
      </td>
    </tr>
 <?php }
 ?>

结果在屏幕截图中

数组结果在下面，带有print_r

$content = array_map(null, $headings, $features_list[$a]);
echo '<pre>';
print_r($content); die;

Array
(
    [0] => Array
        (
            [0] => Heading One
            [1] => Array
                (
                    [0] => Feature 1
                    [1] => Tool Tip for Demo
                    [2] => 0
                )

        )

    [1] => Array
        (
            [0] => Heading Two
            [1] => Array
                (
                    [0] => Feature2
                    [1] => 
                    [2] => 1
                )

        )

    [2] => Array
        (
            [0] => Heading Three
            [1] => Array
                (
                    [0] => Feature 3
                    [1] => 
                    [2] => 0
                )

        )

    [3] => Array
        (
            [0] => 
            [1] => Array
                (
                    [0] => Feature 4
                    [1] => 
                    [2] => 1
                )

        )

)

请帮助我找到问题，为什么我最后要获得阵列。我还有其他函数可以用来替换array_map（）吗？预先特别感谢。