Question

所以我有一个像这样的数组：-

$headers = array();
$headers[] = array("country" => "Netherlands", "city" => "Amsterdam");
$headers[] = array("country" => "Netherlands", "city" => "Tillsburg");
$headers[] = array("country" => "Sweden", "city" => "Stockholm");

我需要它：-

array("country" => "Netherlands", "city" => "Amsterdam,Tillsburg");
array("country" => "Sweden", "city" => "Stockholm");

如何合并值？

这是我到目前为止尝试过的方法，但是似乎没有用。

function merge($headers) {
    $final = [];
    foreach($headers as $current) {
        if(!in_array($current['country'], $final)) {
            $final[] = $current['country'];
        }
  }

  foreach($headers as $current) {
      $final[$current['country']]['city'] = $current['city'];
  }
  return $final;
}

任何帮助将不胜感激。

Answer 1

也许这不是最好的解决方案，但我对其进行了测试，效果很好。

function merge($headers) {
    $final = array();
    foreach ($headers as $current) {
        if( !isset( $final[ $current['country'] ] ) ) {
            $final[$current['country']] = [
                'country' => $current['country'],
                'city'    => $current['city']
            ];
            continue;
      }
      $final[ $current['country'] ]['city'] = $final[ $current['country'] ]['city'] . ', ' . $current['city'];
    }

    return $final;
}

输出

array(2) { ["Netherlands"]=> array(2) { ["country"]=> string(11) "Netherlands" ["city"]=> string(20) "Amsterdam, Tillsburg" } ["Sweden"]=> array(2) { ["country"]=> string(6) "Sweden" ["city"]=> string(9) "Stockholm" } }

如果要添加，可以清除结果数组的键

$final = array_values($final);

在return语句之前

Demo

Answer 2

使用国家/地区值作为临时关联键，以确定是否有必要进行串联。

代码：（Demo）

$headers[] = array("country" => "Netherlands", "city" => "Amsterdam");
$headers[] = array("country" => "Netherlands", "city" => "Tillsburg");
$headers[] = array("country" => "Sweden", "city" => "Stockholm");

foreach ($headers as $row) {
    if (!isset($result[$row['country']])) {
        $result[$row['country']] = $row; // store the whole row
    } else {
        $result[$row['country']]['city'] .= ",{$row['city']}";  // concatenate
    }
}

var_export(array_values($result)); // reindex the output array

输出：

array (
  0 => 
  array (
    'country' => 'Netherlands',
    'city' => 'Amsterdam,Tillsburg',
  ),
  1 => 
  array (
    'country' => 'Sweden',
    'city' => 'Stockholm',
  ),
)

Answer 3

$headers = array();
$headers[] = array("country" => "Netherlands", "city" => "Amsterdam");
$headers[] = array("country" => "Netherlands", "city" => "Tillsburg");
$headers[] = array("country" => "Sweden", "city" => "Stockholm");
$result = array();

foreach($headers as $key => $value) {
    $result[$value['country']][] = $value['city'];
}
$finalArray = array();
foreach($result as $k => $v) {
    $finalArray[] = array('country' => $k, 'city' => join(',', $v));
}

Answer 4

使用国家/地区名称作为键创建另一个数组

<?php
$headers = array();
$headers[] = array("country" => "Netherlands", "city" => "Amsterdam");
$headers[] = array("country" => "Netherlands", "city" => "Tillsburg");
$headers[] = array("country" => "Sweden", "city" => "Stockholm");
$countries = array_unique(array_column($headers,"country"));

$newHeaders = array();
foreach($headers as $header){
    $newHeaders[$header["country"]]["city"][] = $header["city"];
}
print_r($newHeaders);

foreach($newHeaders as $key=>$headers){
    echo $key." City : ".implode(",",$headers['city'])."\n";
}
?>

现场演示Link

输出就像

Netherlands City : Amsterdam,Tillsburg
Sweden City : Stockholm

在同一阵列中合并通用密钥的数据

4 个答案: