如何根据键值合并两个数组（数组值）？答案

【问题标题】：How can I merge two arrays (of array values) based on key value?如何根据键值合并两个数组（数组值）？
【发布时间】：2020-12-01 16:03:46
【问题描述】：

我正在尝试合并这两个数组：

$array1 = array (
  123 => array (
    'minutes_watched' => 192.0,
    'impressions_count' => 18
  ),
  456 => array (
    'minutes_watched' => 200.0,
    'impressions_count' => 20
  )
);

$array2 = array (
  123 => array (
    'ingested_trailers_count' => 3,
    'ingested_shorts_count' => 2,
    'ingested_features_count' => 1
  ),
  456 => array (
    'ingested_trailers_count' => 10,
    'ingested_shorts_count' => 10,
    'ingested_features_count' => 10
  )
);

我想这样结束：

$merged = array (
  123 => array (
    'minutes_watched' => 192.0,
    'impressions_count' => 18,
    'ingested_trailers_count' => 3,
    'ingested_shorts_count' => 2,
    'ingested_features_count' => 1
  ),
  456 => array (
    'minutes_watched' => 200.0,
    'impressions_count' => 20,
    'ingested_trailers_count' => 10,
    'ingested_shorts_count' => 10,
    'ingested_features_count' => 10
  )
);

最终有了这个：

$merged = array (
  array(
    'id' => 123 
    'minutes_watched' => 192.0,
    'impressions_count' => 18,
    'ingested_trailers_count' => 3,
    'ingested_shorts_count' => 2,
    'ingested_features_count' => 1
  ),
  array(
    'id' => 456 
    'minutes_watched' => 200.0,
    'impressions_count' => 20,
    'ingested_trailers_count' => 10,
    'ingested_shorts_count' => 10,
    'ingested_features_count' => 10
  )
);

如果没有一些笨拙的 for 循环，我似乎找不到一种简洁的方法。肯定有一些 PHP 数组函数可以处理这个问题吗？

【问题讨论】：

你需要一个笨重的循环。
567 会发生什么？
道歉 - 似乎我的钥匙都搞砸了 - 再次更正。我想对他们分组。
这能回答你的问题吗？ PHP : multidimensional array merge recursive

标签： php arrays

【解决方案1】：

你可以在一个循环中尝试这样的事情。参见 cmets 的解释。输出：

array(2) {
  [0]=>
  array(6) {
    ["minutes_watched"]=>
    float(192)
    ["impressions_count"]=>
    int(18)
    ["ingested_trailers_count"]=>
    int(3)
    ["ingested_shorts_count"]=>
    int(2)
    ["ingested_features_count"]=>
    int(1)
    ["id"]=>
    int(123)
  }
  [1]=>
  array(6) {
    ["minutes_watched"]=>
    float(200)
    ["impressions_count"]=>
    int(20)
    ["ingested_trailers_count"]=>
    int(10)
    ["ingested_shorts_count"]=>
    int(10)
    ["ingested_features_count"]=>
    int(10)
    ["id"]=>
    int(456)
  }
}

代码：

<?php

// Your input array.
$array1 = array (
  123 => array (
    'minutes_watched' => 192.0,
    'impressions_count' => 18
  ),
  456 => array (
    'minutes_watched' => 200.0,
    'impressions_count' => 20
  )
);

$array2 = array (
  123 => array (
    'ingested_trailers_count' => 3,
    'ingested_shorts_count' => 2,
    'ingested_features_count' => 1
  ),
  456 => array (
    'ingested_trailers_count' => 10,
    'ingested_shorts_count' => 10,
    'ingested_features_count' => 10
  )
);

// Output array
$output = [];

// Loop over first array, assuming all keys from $array1
// exist in $array2.
foreach ($array1 as $key => $child)
{
    // Combine the two arrays, preserving keys.
    $merged = $array1[$key] + $array2[$key];
    // Copy key to 'id' element.
    $merged['id'] = $key;
    // Add to output.
    $output[] = $merged;
}

var_dump($output);

/*
array(2) {
  [0]=>
  array(6) {
    ["minutes_watched"]=>
    float(192)
    ["impressions_count"]=>
    int(18)
    ["ingested_trailers_count"]=>
    int(3)
    ["ingested_shorts_count"]=>
    int(2)
    ["ingested_features_count"]=>
    int(1)
    ["id"]=>
    int(123)
  }
  [1]=>
  array(6) {
    ["minutes_watched"]=>
    float(200)
    ["impressions_count"]=>
    int(20)
    ["ingested_trailers_count"]=>
    int(10)
    ["ingested_shorts_count"]=>
    int(10)
    ["ingested_features_count"]=>
    int(10)
    ["id"]=>
    int(456)
  }
}
*/

【讨论】：

这很接近，但我不能假设每个键都存在于任一数组中。

【解决方案2】：

我最终得到了这个解决方案：

  $merged = array_replace_recursive($arrayOne, $arrayTwo);

  $flattened = array_map(function($key, $value) {
      return array_merge($value, [
          'id' => $key
      ]);
  }, array_keys($merged), $merged);

我对@987654322@ 部分感觉不太好，但是...

【讨论】：

这是很多不必要的嵌套循环。