檢查數組中的相同值

Question

我有以下數組：

$teams = [["id" => 1, "address" => "A1"],["id" => 2, "address" => "A1"],["id" => 3, "address" => "A2"]];

如何檢查並獲得具有相同地址的團隊？ 我的輸出應該是團隊ID 1和2？ 考慮到我不能使用硬編碼地址。 數據是動態的，並且來自數據庫。

在php中，laravel。

先感謝您！

Answer 1

首先，您需要按其address分組，然后可以使用array_filter()根據條件截斷數組：

<?php
$teams = [["id" => 1, "address" => "A1"],["id" => 2, "address" => "A1"],["id" => 3, "address" => "A2"]];

// Set a new array
$filtered = [];

// Loop the teams
foreach($teams as $v)
{
    // Group the teams into their respective addresses
    $filtered[$v['address']][] = $v;
}

// Filter out any address with 1 or fewer teams
$filtered = array_filter($filtered, function($v){
    return count($v) > 1;
});

print_r($filtered);

// Now you can loop $filtered and display whatever you want

輸出：

Array
(
    [A1] => Array
        (
            [0] => Array
                (
                    [id] => 1
                    [address] => A1
                )

            [1] => Array
                (
                    [id] => 2
                    [address] => A1
                )

        )

)

Answer 2

另一種方法是使用array_column()和array_count_values() 。 然后使用array_filter()刪除沒有重復的元素：

$teams = [
 ["id" => 1, "address" => "A1"],
 ["id" => 2, "address" => "A1"] ,
 ["id" => 3, "address" => "A2"]
];

$dups = array_count_values(array_column($teams, 'address'));
$teams = array_filter($teams, function($item) use($dups) {
    return $dups[$item['address']] > 1;
});
print_r($teams);

輸出（重新格式化）：

Array
(
    [0] => Array([id] => 1, [address] => A1)
    [1] => Array([id] => 2, [address] => A1)
)

Answer 3

遍歷數組，記住哪個團隊使用哪個地址。 當一個密鑰（地址）中存儲了多個團隊時，您會發現一個重復的副本：

<?php
$teams = [
     ["id" => 1, "address" => "A1"]
    ,["id" => 2, "address" => "A1"]
    ,["id" => 3, "address" => "A2"]
  ];

function findDuplicates($teams) {
  $addresses = [];
  foreach ($teams as $team) {
    if (!isset($addresses[$team["address"]])) {
      $addresses[$team["address"]] = [];
    }
    $addresses[$team["address"]][] = $team["id"];
  }
  foreach ($addresses as $address => $teamsHere) {
    if (count($teamsHere) > 1) {
      echo "Teams with same address (" . $address . "): " . join(",", $teamsHere) . "\n";
    }
  }
}

findDuplicates($teams);

在線嘗試！

---

編輯：使用array_*函數的一種不太“笨拙”的方法：

<?php
$teams = [
     ["id" => 1, "address" => "A1"]
    ,["id" => 2, "address" => "A1"]
    ,["id" => 3, "address" => "A2"]
  ];

function findDuplicates($teams) {
  $addresses = array_column($teams, "address");
  $counts = array_count_values($addresses);
  return array_filter($teams, function($team) use ($counts) { return $counts[$team["address"]] > 1; });
}

print_r(findDuplicates($teams));

在線嘗試！