獲取具有某個關鍵值的所有值

Question

因此，我一直試圖弄清楚這一點，現在似乎被卡住了。我有一個multidimensionalarray，我試圖用特定的鍵輸出所有的值。下面是代碼：

//My Array: 
$services = array(
       array( service_name => 'facebook', 
        service_title => 'Facebook', 
        service_order => 0, 
        service_type => 'Social Networking' 
        ), 
       array( service_name => 'twitter', 
        service_title => 'Twitter', 
        service_order => 0, 
        service_type => 'Social Networking' 
        ), 
       array( service_name => 'tumblr', 
        service_title => 'MySpace', 
        service_order => 0, 
        service_type => 'Blogging' 
        ) 
); 

的問題是我要輸出的值由service_type例如「社交網絡」或「博客」我能，如果我使用一個foreach語句，像這樣做：

foreach($services as $service) { 
    if ($service['service_type'] == 'Social Networking') { 
      echo($service['service_title']); 
    } 
    if ($service['service_type'] == 'Blogging') { 
      echo($service['service_title']); 
    } 
} 

，直到我嘗試在類型之間添加標題像

foreach($services as $service) { 
    if ($service['service_type'] == 'Social Networking') { 
      echo($service['service_title']); 
    } 
    echo ('<h3> Blogging</h3>'); 
    if ($service['service_type'] == 'Blogging') { 
      echo($service['service_title']); 
    } 
} 

我已經瞭解了足夠知道的正常工作是因爲方式foreach循環工作，所以我一直在嘗試用while($service['service_type'] == 'Social Networking')（創建一個有趣的無限循環）和其他各種方式來做到這一點。

理想情況下，我想按service_type對數組排序，然後顯示結果，而不必在標題之間運行foreach循環。

對此的任何幫助將是令人敬畏的甚至是其他方式的建議。

Answer 1

我認爲你正在嘗試做這樣的事情：

// Create an array containing all of the distinct "service types" 
// from the $services array 
$service_types = array(); 
foreach ($services as $service) { 
    // If we have not yet encountered this entry's "service type", 
    // then we need to add it to our new array 
    if (!in_array($service['service_type'], $service_types)) { 
     $service_types[] = $service['service_type']; 
    } 
} 
if (count($service_types)) { 
    // For each "service type", we want to echo a header and then 
    // a list of services of that type 
    foreach ($service_types as $current_type) { 
     echo '<h3>'.$current_type.'</h3>'; 
     // Loop through the services and echo those that are 
     // of the correct type 
     foreach ($services as $service) { 
      if ($service['service_type'] == $current_type) { 
       echo($service['service_title']); 
      } 
     } 
    } 
} else { 
    echo '<h3>No services</h3>' 
} 

Answer 2

我沒有跟着你所有的問題，但你問，如果你可以根據業務類型數組排序 - 這樣你就可以建立一個user defined sorting function。

function sortByServiceType($a, $b) { 
    // This will sort them by service type alphabetically 
    return strcmp($a['service_type'], $b['service_type']); 
} 

uasort($services, 'sortByServiceType'); 

Answer 3

用PHP> 5.5，你可以做

$myData = array(
    array(
     'service_name' => 'facebook', 
     'service_title' => 'Facebook', 
     'service_order' => 0, 
     'service_type' => 'Social Networking' 
    ), 
    array( 
     'service_name' => 'twitter', 
     'service_title' => 'Twitter', 
     'service_order' => 0, 
     'service_type' => 'Social Networking' 
    ), 
    array(
     'service_name' => 'tumblr', 
     'service_title' => 'MySpace', 
     'service_order' => 0, 
     'service_type' => 'Blogging' 
    ) 
); 

$filtered = array_column($myData, 'service_column'); 

見：http://www.php.net/manual/en/function.array-column.php