在PHP中，我有一个名为$listing的二维数组，它将包含具有以下结构的数据：
(
[1] => Array
(
[category] => tech
[business_name] => Apple
)
[2] => Array
(
[category] => food
[business_name] => McDonalds
)
[3] => Array
(
[category] => tech
[business_name] => Dell
)
)
我想以纯文本形式输出，按类别（按字母顺序排列）和*business_name*（按字母排序）分组。请注意，这只是它将如何显示的一个子集——可能有50个类别和1000个列表——所以代码需要考虑到这一点。
因此，使用上面列出的$listing的输出，我需要它输出如下：
category: food
business_name: McDonalds
category: tech
business_name: Apple
business_name: Dell
请帮忙。提前谢谢。
有很多方法可以做到这一点，但这应该让你开始。
$data = array();
foreach ($listing as $item) {
$data[$item['category']][] = $item['business_name'];
}
ksort($data);
$data = array_map(function($names) {
sort($names);
return $names;
}, $data);
未测试。。。
了解PHP多数组排序http://www.php.net/manual/en/function.array-multisort.php要对数组进行多重排序，请查看这是否有助于
我使用了array_multsort（）作用看看下面的代码。
<?php
//array to sort
$data[0] = array('category'=> 'tech','business_name' => 'apple') ;
$data[1] = array('category'=> 'food','business_name' => 'McDonalds') ;
$data[2] = array('category'=> 'tech','business_name' => 'dell') ;
$data[3] = array('category'=> 'food','business_name' => 'subway') ;
foreach($data as $key => $val){
$cat[$key] = $val['category'];
$bus[$key] = $val['business_name'];
}
// Sort the data with category and business_name with ascending order
array_multisort($cat, SORT_ASC, $bus, SORT_ASC, $data);
// echo "<pre>";print_r($data);echo "</pre>";unset($val);
//put the category as key And business name as value with comma seperated.
$category = array();
foreach($data as $key => $val){
if(array_key_exists($val['category'],$category ))
{
$category[$val['category']] = $category[$val['category']].', '.$val['business_name'];
}
else
{
$category[$val['category']] = $val['business_name']; // $category
}
}
//print the sorted data
foreach($category as $key => $val){
//print category
echo "<br /> <br />Category: ".$key;
$b_name = explode(',', $val);
//to print busniess name
foreach($b_name as $k => $v){
echo "<br />Business Name: ".$v;
}
}
?>
//OUTPUT
Category: food
Business Name: McDonalds
Business Name: subway
Category: tech
Business Name: apple
Business Name: dell