如何用特定键求和数组值

Question

"accounts" => array:6 [
    0 => array:2 [
      "acc_id" => 1
      "balance" => 1000.00
    ]
    1 => array:2 [
      "acc_id" => 2
      "balance" => -1500.00
    ]
    2 => array:4 [
      "acc_id" => 3
      "balance" => 5000.00
    ]
]

嗨，我该如何总结所有正确的余额？

代码

foreach ($y['accounts'] as $k) 
{
    $sum_balance = $k['balance'];           
}
$sum_balance += $sum_balance;

使用此代码，结果将只累加最后一个余额本身。示例结果为10000.00

Answer 1

您需要在foreach循环中增加总和：

$sum_balance = 0;
foreach ($y['accounts'] as $k) 
{
    $sum_balance += $k['balance'];           
}
var_dump($sum_balance);

Answer 2

将array_sum()与array_column()组合

array_column()

  

从输入数组的单个列中返回值

array_sum()

  

计算数组中的值之和

$y = [
    'accounts' => [
        0 => [
          "acc_id" => 1,
          "balance" => 1000.00
        ],
        1 => [
          "acc_id" => 2,
          "balance" => -1500.00
        ],
        2 => [
          "acc_id" => 3,
          "balance" => 5000.00
        ]
    ]
];

var_dump(
    array_sum(array_column($y['accounts'], 'balance'))
);

结果：float 4500

Answer 3

您的解决方案几乎是正确的，只需在循环之前初始化$sum_balance并在循环内求和。

$sum_balance=0;
foreach ($y['accounts'] as $k) 
{
    $sum_balance += $k['balance'];           
}

希望它会有所帮助，如果您需要任何帮助，请随时联系。