PHP-如果数组中的值相同，如何分组

编程问答 2022-06-10

问题描述

这是我的数组示例

Array
(
  [0] => Array ( [_id] => 5f76b1788ee23077dccd1a2c [product] => Array ( [0] => Array ( [_id] => 5d0391a4a72ffe76b8fcc610 ) ) [count] => 1 )
  [1] => Array ( [_id] => 5f76b6288ee2300700cd1a3a [product] => Array ( [0] => Array ( [_id] => 5d0391b6a72ffe76b8fcc611 ) ) [count] => 1 )
  [2] => Array ( [_id] => 5f76d2488ee23083d3cd1a4a [product] => Array ( [0] => Array ( [_id] => 5d0391b6a72ffe76b8fcc611 ) ) [count] => 1) 
)

如果产品价值相同，我想分组，

Array
(
  [0] => Array ( [_id] => 5f76b1788ee23077dccd1a2c [product] => Array ( [0] => Array ( [_id] => 5d0391a4a72ffe76b8fcc610 ) ) [count] => 1 )
  [1] => Array ( [_id] => 5f76b6288ee2300700cd1a3a [product] => Array ( [0] => Array ( [_id] => 5d0391b6a72ffe76b8fcc611 ) ) [count] => 2 )
)

解决方法

保留第一级ID是没有意义的，因为您在合并过程中会随意丢弃某些第一级ID（破坏关系）。

相反，我建议您仅隔离准确相关的数据。

如果此输出不能满足您的需求，那么我将要求进一步澄清问题。

通过为输出数组分配临时键，输出数组还可以用作查找数组，您可以通过该数组快速检查唯一性。首次遇到ID时，“空合并运算符”（??）设置后备值0 －这样可防止生成有关未声明密钥的任何警告。

代码：（Demo）

$array = [
    ['_id' => '5f76b1788ee23077dccd1a2c','product' => ['_id'=>'5d0391a4a72ffe76b8fcc610'],'count'=> 1],['_id' => '5f76b6288ee2300700cd1a3a','product' => ['_id'=>'5d0391b6a72ffe76b8fcc611'],['_id' => '5f76d2488ee23083d3cd1a4a','count'=> 1]
];

$productCounts = [];
foreach ($array as $item) {
    $productId = $item['product']['_id'];
    $productCounts[$productId] = ($productCounts[$productId] ?? 0) + $item['count'];
}

var_export($productCounts);

输出：

array (
  '5d0391a4a72ffe76b8fcc610' => 1,'5d0391b6a72ffe76b8fcc611' => 2,)

如果您在问题中坚持期望的输出，那么它可以像这样简单而有效...

代码：（Demo）

$result = [];
foreach ($array as $item) {
    $productId = $item['product']['_id'];
    if (!isset($result[$productId])) {
        $result[$productId] = $item;
    } else {
        $result[$productId]['count'] += $item['count'];
    }
}

var_export(array_values($result));

输出：

array (
  0 => 
  array (
    '_id' => '5f76b1788ee23077dccd1a2c','product' => 
    array (
      '_id' => '5d0391a4a72ffe76b8fcc610',),'count' => 1,1 => 
  array (
    '_id' => '5f76b6288ee2300700cd1a3a','product' => 
    array (
      '_id' => '5d0391b6a72ffe76b8fcc611','count' => 2,)
,

您可以尝试以下代码，它会为您工作：-）

<?php
$Myarray = array(['_id'=> '5f76b1788ee23077dccd1a2c','product'=> ['_id'=>'5d0391a4a72ffe76b8fcc610'],'count'=> 1 ],['_id'=> '5f76b6288ee2300700cd1a3a','product'=> ['_id'=>'5d0391b6a72ffe76b8fcc611'],['_id'=> '5f76d2488ee23083d3cd1a4a','count'=> 1 ]
);

$user_array = [];
$temp_array = [];
foreach($Myarray as $temp)
{
    $found = array_search($temp['product']['_id'],$temp_array);
    if($found !== false)
    {
        $i = 0;
        foreach($user_array as $temp1)
        {
            if($temp1['product']['_id'] == $temp['product']['_id'])
            {
                $sum = $temp1['count'] + 1;
                $user_array[$i]['count'] = $sum;
            }
            $i++;
        }
    }
    else
    {
        array_push($user_array,$temp);
        array_push($temp_array,$temp['product']['_id']);
    }
}
print_r($user_array);
?>

这将在输出下方产生

Array（[0] => Array（[_id] => 5f76b1788ee23077dccd1a2c [product] => Array（[_id] => 5d0391a4a72ffe76b8fcc610）[count] => 1）[1] => Array（[_id] = > 5f76b6288ee2300700cd1a3a [product] =>数组（[_id] => 5d0391b6a72ffe76b8fcc611 [count] => 2））

array-mergearray-sumgroupingmultidimensional-array