按属性名称求和数组值

Question

我想用相同的代码对计数值求和。

这是我的数组：

$data = array(

    array(

        'code' => 02,

        'count' => 8

    ),

    array(

        'code' => 03,

        'count' => 1

    ),

    array(

        'code' => 03,

        'count' => 1

    ),

    array(

        'code' => 03,

        'count' => 7

    ),

    array(

        'code' => 11,

        'count' => 1

    ),

    array(

        'code' => 11,

        'count' => 5

    ),

    array(

        'code' => 17,

        'count' => 4

    ),

    array(

        'code' => 17,

        'count' => 2

    ),

    array(

        'code' => 17,

        'count' => 8

    )

);

现在我尝试对数组进行分组以count使用相同的代码求和，但我认为我错了：

$new_data = [];    

foreach($data as $k => $v){

    $total = 0;

    $new_data[$v['code']] = array(

        'ttl' => $v['count'] + $total,

    );

}

echo '<pre>';

print_r($new_data);

echo '</pre>';

正确的代码是什么？谢谢。

Answer 1

使用isset将避免未定义的偏移错误：$new_data = [];foreach($data as $k => $v){&nbsp; &nbsp; if (!isset($new_data[$v['code']]['ttl'])){&nbsp; &nbsp; &nbsp; &nbsp; $new_data[$v['code']]['ttl'] = 0;&nbsp; &nbsp; }&nbsp; &nbsp; $new_data[$v['code']]['ttl'] += $v['count'];}print_r($new_data);

Answer 2

假设您希望 to 中的键$new_data是唯一的代码，并且值是一个数组，ttl其键的值是该特定代码的计数总和：$new_data = [];&nbsp; &nbsp;&nbsp;foreach($data as $v){&nbsp; &nbsp; if (!array_key_exists($v['code'], $new_data)) {&nbsp; &nbsp; &nbsp; &nbsp; $new_data[$v['code']]['ttl'] = $v['count'];&nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; $new_data[$v['code']]['ttl'] += $v['count'];&nbsp; &nbsp; }}

Answer 3

我认为这就是您想要的输出：Array(&nbsp; &nbsp; [2] => Array&nbsp; &nbsp; &nbsp; &nbsp; (&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; [ttl] => 8&nbsp; &nbsp; &nbsp; &nbsp; )&nbsp; &nbsp; [3] => Array&nbsp; &nbsp; &nbsp; &nbsp; (&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; [ttl] => 9&nbsp; &nbsp; &nbsp; &nbsp; )&nbsp; &nbsp; [11] => Array&nbsp; &nbsp; &nbsp; &nbsp; (&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; [ttl] => 6&nbsp; &nbsp; &nbsp; &nbsp; )&nbsp; &nbsp; [17] => Array&nbsp; &nbsp; &nbsp; &nbsp; (&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; [ttl] => 14&nbsp; &nbsp; &nbsp; &nbsp; ))如果是这样，您可以对代码进行少量修改，如下所示：$new_data = [];foreach ($data as $d) {&nbsp; &nbsp; if (isset($new_data[$d['code']]['ttl'])) {&nbsp; &nbsp; &nbsp; &nbsp; $new_data[$d['code']]['ttl'] += $d['count'];&nbsp; &nbsp; } else {&nbsp; &nbsp; &nbsp; &nbsp; $new_data[$d['code']]['ttl'] = $d['count'];&nbsp; &nbsp; }}