比较两个数组并查找特定值中的所有重复项（php）答案

【问题标题】：Compare two arrays and find all duplicates in a sepcific value (php)比较两个数组并查找特定值中的所有重复项（php）
【发布时间】：2019-04-06 04:43:56
【问题描述】：

我有两个数组，第一个是旧的，第二个是新的。我想比较它们并只输出重复项。

我尝试了一些痛苦的事情：array_intersect 和 array_search 没有任何结果...

第一个数组（旧）包含作为输出：

[0] => Array (
    [id] => old_id_1
    [color] => red
 )

[1] => Array (
    [id] => old_id_2
    [color] => blue
 )

[2] => Array (
    [id] => old_id_3
    [color] => green
 )

[3] => Array (
    [id] => old_id_4
    [color] => purple
 )

[4] => Array (
    [id] => old_id_5
    [color] => yellow
 )

第二个（新），输出：

[0] => Array (
    [id] => new_id_1
    [color] => blue
)


[1] => Array (
    [id] => new_id_2
    [color] => pink
)


[2] => Array (
    [id] => new_id_3
    [color] => purple
)

作为回报，我想做一些类似的东西：

We find 2 duplicates colors :
-  blue (new_id_1) in old_id_2 
-  purple (new_id_3) in old_id_4

如果有人有一些想法。

【问题讨论】：

标签： php arrays multidimensional-array duplicates key-value

【解决方案1】：

试试这个：

$firstArr  = [
    ['id' => 'old_id_1', 'color' => 'red'],
    ['id' => 'old_id_2', 'color' => 'blue'],
    ['id' => 'old_id_3', 'color' => 'green'],
    ['id' => 'old_id_4', 'color' => 'purple'],
    ['id' => 'old_id_5', 'color' => 'yellow'],
];
$secondArr = [
    ['id' => 'new_id_1', 'color' => 'blue'],
    ['id' => 'new_id_2', 'color' => 'pink'],
    ['id' => 'new_id_3', 'color' => 'purple'],
];

$firstArrAssoc = array_combine(array_column($firstArr, 'color'), array_column($firstArr, 'id'));
$duplicatesArr = [];
foreach ($secondArr as $row) {
    if (array_key_exists($row['color'], $firstArrAssoc)) {
        $duplicatesArr[] = "-  $row[color] ($row[id]) in {$firstArrAssoc[$row['color']]}";
    }
}
echo "We find " . count($duplicatesArr) . " duplicates colors :\n";
echo implode("\n", $duplicatesArr);

输出：

We find 2 duplicates colors :
-  blue (new_id_1) in old_id_2
-  purple (new_id_3) in old_id_4

Try it with 3v4l.org

【讨论】：