PHP：将数据数组拆分为字母顺序

Posted 2023-05-09

【中文标题】PHP：将数据数组拆分为字母顺序

【英文标题】：PHP: Split array of data into alphabetical order

【发布时间】：2012-05-17 11:53:16

【问题描述】：

我的应用程序中有以下代码，它将按字母顺序显示主题列表，并按每个部分块中的第一个标签名称对其进行拆分。

例如：

A
animal
amazing

B
bat
baseball

代码如下：

<?php

    foreach($topics as $currentTopic):
        $thisLetter = strtoupper($currentTopic['Topic']['title'][0]);
        $sorted[$thisLetter][] = $currentTopic['Topic']['title'];
        unset($thisLetter);
    endforeach;

    foreach($sorted as $key=>$value):

        echo '<h3 class="alpha"><span>'.$key.'</span></h3>';
        echo '<ol class="tags main">';

        foreach($value as $thisTopic):

            echo '<li class="tag"><em>0</em>';
            echo $this->html->link('<strong>'.$thisTopic['Topic']['title'].'</strong>',
                        array('controller'=>'topics','action'=>'view','slug'=>$thisTopic['Topic']['slug']),
                        array('escape'=>false,'rel'=>'tag'));
            echo '</li>';
        endforeach;

        echo '</ol>';

    endforeach;

    ?>

但是，由于我现在已经拆分了数组，我发现很难访问数组中的其他数据，例如用于链接的主题 slug，因为 $thisTopic 变量只存储标题和其他所需数据。我还想在<em> 中显示 TopicPost 计数，因此如果某个主题有 4 个相关帖子，则显示 <em>4</em>

目前正在做的事情给出了错误：Fatal error: Cannot use string offset as an array 因为我已经拆分了数组...

谁能帮忙？

如果我调试 $topics 数组，我会得到以下信息：

array(
    (int) 0 => array(
        'Topic' => array(
            'id' => '5',
            'title' => 'amazing',
            'slug' => 'amazing'
        ),
        'TopicPost' => array(
            (int) 0 => array(
                'id' => '9',
                'topic_id' => '5',
                'post_id' => '101'
            )
        )
    ),
    (int) 1 => array(
        'Topic' => array(
            'id' => '4',
            'title' => 'amazingness',
            'slug' => 'amazingness'
        ),
        'TopicPost' => array(
            (int) 0 => array(
                'id' => '8',
                'topic_id' => '4',
                'post_id' => '100'
            ),
            (int) 1 => array(
                'id' => '12',
                'topic_id' => '4',
                'post_id' => '101'
            ),
            (int) 2 => array(
                'id' => '4',
                'topic_id' => '4',
                'post_id' => '119'
            )
        )
    ),...

【参考方案1】：

您收到错误是因为您只存储主题的标题。

我建议存储整个主题信息，而不仅仅是标题：

$orderedTopics= array();
foreach ($topics as $topic) 
  $orderedTopics[strtoupper($topic['Topic']['title'][0])][] = $topic;

然后，显示它：

foreach ($orderedTopics as $section=>$topics) 
  echo $section;
  foreach ($topics as $topic) 
    echo 'Title: ' . $topic['Topic']['title'];
    echo 'Body: ' . $topic['Topic']['body'];
    //etc...