PHP中合并多数组相同variant_id的quantity与price的方法

需求说明 #

你需要将多个子数组中相同variant_id的条目合并：

• 相同variant_id对应的quantity进行累加
• price保持与原条目一致（假设同一variant_id的price都是相同的，如你的示例数据）

输入示例 #

$inputArray = Array (
    [0] => Array ( [variant_id] => 30929149493321 [quantity] => 1 [price] => 299.00 ),
    [1] => Array ( [variant_id] => 19663805153353 [quantity] => 1 [price] => 99.00 ),
    [2] => Array ( [variant_id] => 19663804989513 [quantity] => 6 [price] => 99.00 ),
    [3] => Array ( [variant_id] => 30929149493321 [quantity] => 1 [price] => 299.00 ),
    [4] => Array ( [variant_id] => 19663805153353 [quantity] => 1 [price] => 99.00 ),
    [5] => Array ( [variant_id] => 31108834754633 [quantity] => 1 [price] => 379.05 )
);

期望输出 #

Array (
    [0] => Array ( [variant_id] => 30929149493321 [quantity] => 2 [price] => 299.00 ),
    [1] => Array ( [variant_id] => 19663805153353 [quantity] => 2 [price] => 99.00 ),
    [2] => Array ( [variant_id] => 19663804989513 [quantity] => 6 [price] => 99.00 ),
    [3] => Array ( [variant_id] => 31108834754633 [quantity] => 1 [price] => 379.05 )
);

解决方案代码 #

这里用一个高效的循环实现，利用variant_id作为临时数组的键来快速判断重复：

// 你的原始输入数组
$inputArray = [
    ['variant_id' => 30929149493321, 'quantity' => 1, 'price' => 299.00],
    ['variant_id' => 19663805153353, 'quantity' => 1, 'price' => 99.00],
    ['variant_id' => 19663804989513, 'quantity' => 6, 'price' => 99.00],
    ['variant_id' => 30929149493321, 'quantity' => 1, 'price' => 299.00],
    ['variant_id' => 19663805153353, 'quantity' => 1, 'price' => 99.00],
    ['variant_id' => 31108834754633, 'quantity' => 1, 'price' => 379.05],
];

$mergedArray = [];

foreach ($inputArray as $item) {
    $id = $item['variant_id'];
    
    // 如果当前variant_id已存在，累加quantity
    if (isset($mergedArray[$id])) {
        $mergedArray[$id]['quantity'] += $item['quantity'];
    } else {
        // 不存在则直接添加条目，用variant_id作为临时键
        $mergedArray[$id] = $item;
    }
}

// 将关联数组转为数字索引数组，匹配期望输出格式
$mergedArray = array_values($mergedArray);

// 打印结果
print_r($mergedArray);

代码说明 #

1. 临时数组键的使用：用variant_id作为$mergedArray的键，这样可以在O(1)时间内判断该条目是否已存在，避免嵌套循环，提升效率。
2. 累加逻辑：如果条目已存在，只需要对quantity进行累加操作，price因为同一variant_id值一致，无需修改。
3. 索引重置：最后用array_values()将关联数组转换为数字索引数组，和你期望的输出格式完全匹配。

内容的提问来源于stack exchange，提问作者Muneeb Ahmad