按值合并单个数组对象并在子数组中保留重复项

Question

我有以下（简化的）数组：

$myArray = array(
   0=> array( 
      'userid' => '12',
      'favcolor' => 'green'
   ),
   1=> array( 
      'userid' => '62',
      'favcolor' => 'orange'
   ),
   2=> array( 
      'userid' => '12',
      'favcolor' => 'red'
   ),
   3=> array( 
      'userid' => '62',
      'favcolor' => 'blue'
   ),
)

我想通过存在的公共用户标识值合并数组并保留最喜欢的颜色信息。我试过的其他方法只保留数组中的第一个 favcolor 值。看起来很简单，但无法找到快速解决方案。

预期输出：

$myArray = array(
   0=> array( 
      'userid' => '12',
      'favcolor' => array('green', 'red')
   ),
   1=> array( 
      'userid' => '62',
      'favcolor' => array('orange', 'blue')
   ),
)

如果不使用另一个数组进行比较，这可能吗？

Answer 1

这里我们使用简单的foreach来合并并达到预期的结果，通过使用这个数组的userid作为key。这里我们使用 array_values 来删除那些密钥。

Try this code snippet here

<?php

ini_set('display_errors', 1);

$myArray = array(
   0=> array( 
      'userid' => '12',
      'favcolor' => 'green'
   ),
   1=> array( 
      'userid' => '62',
      'favcolor' => 'orange'
   ),
   2=> array( 
      'userid' => '12',
      'favcolor' => 'red'
   ),
   3=> array( 
      'userid' => '62',
      'favcolor' => 'blue'
   ),
);
$result=array();
foreach($myArray as $value)
{
    //check for previous existence of key in resultant array
    //if key not exist then put value on that key and using favcolor as array
    if(!isset($result[$value["userid"]]))of key in a array.
    {
        $result[$value["userid"]]=array("userid"=>$value["userid"],"favcolor"=>array($value["favcolor"]));
    }
    //if key already exists then just adding favcolor values to that key
    else
    {
        $result[$value["userid"]]["favcolor"][]=$value["favcolor"];
    }
}
print_r(array_values($result));

输出：

Array
(
    [0] => Array
        (
            [userid] => 12
            [favcolor] => Array
                (
                    [0] => green
                    [1] => red
                )

        )

    [1] => Array
        (
            [userid] => 62
            [favcolor] => Array
                (
                    [0] => orange
                    [1] => blue
                )

        )

)

Answer 2

只需按如下操作即可

// Creating an array for result
foreach($myArray as $ar){
    if(!isset($aa[$ar['userid']])) $aa[$ar['userid']] = [];
    if(!in_array($ar['favcolor'],$aa[$ar['userid']])) $aa[$ar['userid']][] = $ar['favcolor'];
}

// Designing it according to result
foreach($aa as $arr=>$val)
    $last[] =  ['userid'=>$arr,'favcolor'=>$val];

echo '<pre>';
var_dump($last);

按值合并单个数组对象并在子数组中保留重复项

Merge single array objects by value and preserve duplicates in sub array

php

arrays

sorting

merge

unique