PHP单独的数组元素基于共同价值观

Question

我有以下阵列从数据库中来：

$tags = Array 
    (
     [0] => Array 
      (
       [id] => 1 
       [tag_name] => Testing/EOC 
       [description] => 
       [category] => Category 1 
      ) 

     [1] => Array 
      (
       [id] => 2 
       [tag_name] => Technology Tips 
       [description] => 
       [category] => Category 1 
      ) 

     [2] => Array 
      (
       [id] => 3 
       [tag_name] => Student Engagement 
       [description] => 
       [category] => Category 1 
      ) 

     [3] => Array 
      (
       [id] => 4 
       [tag_name] => Flipped Classroom 
       [description] => 
       [category] => Category 1 
      ) 

     [4] => Array 
      (
       [id] => 5 
       [tag_name] => Blended Instruction 
       [description] => 
       [category] => Category 1 
      ) 

     [5] => Array 
      (
       [id] => 6 
       [tag_name] => Differentiated Instruction 
       [description] => 
       [category] => Category 1 
      ) 

     [6] => Array 
      (
       [id] => 7 
       [tag_name] => Bootcamp 
       [description] => 
       [category] => Category 1 
      ) 

     [7] => Array 
      (
       [id] => 8 
       [tag_name] => Mathematical Practices 1 
       [description] => 
       [category] => Category 1 
      ) 

     [8] => Array 
      (
       [id] => 9 
       [tag_name] => Mathematical Practices 2 
       [description] => 
       [category] => Category 2 
      ) 

     [9] => Array 
      (
       [id] => 10 
       [tag_name] => Mathematical Practices 3 
       [description] => 
       [category] => Category 2 
      ) 

     [10] => Array 
      (
       [id] => 11 
       [tag_name] => Mathematical Practices 4 
       [description] => 
       [category] => Category 2 
      ) 

     [11] => Array 
      (
       [id] => 12 
       [tag_name] => Mathematical Practices 5 
       [description] => 
       [category] => Category 2 
      ) 

     [12] => Array 
      (
       [id] => 13 
       [tag_name] => Mathematical Practices 6 
       [description] => 
       [category] => Category 2 
      ) 

     [13] => Array 
      (
       [id] => 14 
       [tag_name] => Mathematical Practices 7 
       [description] => 
       [category] => Category 2 
      ) 

     [14] => Array 
      (
       [id] => 15 
       [tag_name] => Mathematical Practices 8 
       [description] => 
       [category] => Category 2 
      ) 

     [15] => Array 
      (
       [id] => 16 
       [tag_name] => Pre-Algebra 
       [description] => 
       [category] => Category 3 
      ) 

     [16] => Array 
      (
       [id] => 17 
       [tag_name] => Sets and Venn Diagrams 
       [description] => 
       [category] => Category 3 
      ) 
    ) 

现在我只是循环，通过像这样：

<ul> 
        <? foreach($tags as $tag): ?> 
         <li> 
          <input type="checkbox" class="tag" name="tags[]" value="<?= $tag['id']; ?>"> 
          <label><?= $tag['tag_name']; ?></label> 
         </li> 
        <? endforeach; ?> 
</ul> 

不过，我真正想要做的是将标签分开，并根据三个不同的类别将它们分为三个部分（可能是他们自己的独立部门）。基本上我想要有三个列，每个都有类别名称作为标题，并在其下面列出适当的标签。不知道如何在循环中实现这一点，并将它们全部保持为同一形式的输入。

$categoryToTag = array(); 
foreach ($tags as $tag) { 
    if (!isset($categoryToTag[$tag['category']])) $categoryToTag[$tag['category']] = array(); 
    $categoryToTag[$tag['category']][] = $tag; 
} 

2遍历的类别和输出标签：

foreach ($categoryToTag as $category => $categoryTags) { 
    echo 'Category '.$category.' begin'; 
    foreach ($categoryTags as $tag) echo $tag; 
} 

Answer 1

1组他们按类别

<table> 
<?php 
// group the sub-arrays of your initial array by category 
$cats = array(); 
foreach($tags as $tag){ 
$cats[$tag["category"]][] = array($tag["id"], $tag["tag_name"]); 
} 
// display the names of the categories in the header row of the table 
print("<tr><th>".implode("</th><th>", array_keys($cats))."</th></tr>"); 
// create another row 
print("<tr>"); 
// iterate over the categories – display each category in a single table cell 
foreach($cats as $cat){ 
print("<td>"); 
// iterate over the sub-arrays of each category 
    foreach($cat as $val){ 
    print("<input type=\"checkbox\" class=\"tag\" name=\"tags[]\" value=\"{$val[0]}\"> 
          <label>{$val[1]}</label><br/>"); 
    } 
print("</td>"); 
} 
print("</tr>"); 
?> 
</table> 

Answer 2

您可以考虑使用一个表：