如何获得二维数组的总和

Question

我有两个数组

Array
(
    [0] => Array
        (
            [0] => 7
            [1] => 8
        )

    [1] => Array
        (
            [0] => 6
            [1] => 3
        )

)
Array
(
    [0] => Array
        (
            [0] => 4
            [1] => 7
        )

    [1] => Array
        (
            [0] => 8
            [1] => 3
        )

)

并希望将其在外部数组中的索引值求和为

Array
(
    [0] => 13
    [1] => 11
)
Array
(
    [0] => 12
    [1] => 10
)

为此我在做什么

 $sum_inhale=array();
 foreach($x_inhale as $k=>$sub_array)
 { 
    foreach($sub_array as $id => $val)
    {
        $sum_inhale[$id] += $val; //<---Error occured here
    }
 }
 print_r($sum_inhale);

但我也收到通知为什么？

<div style="border:1px solid #990000;padding-left:20px;margin:0 0 10px 0;">

<h4>A PHP Error was encountered</h4>

<p>Severity: Notice</p>
<p>Message:  Undefined offset: 0</p>
<p>Filename: controllers/Report.php</p>
<p>Line Number: 463</p>

<p>Backtrace:</p>

<p style="margin-left:10px">
File: C:\xampp\htdocs\newyogapanel\application\controllers\Report.php<br />
Line: 463<br />
Function: _error_handler 
</p>


<p style="margin-left:10px">
File: C:\xampp\htdocs\newyogapanel\index.php<br />
Line: 315<br />
Function: require_once 
</p>

</div>

Answer 1

您可以将array_column()与array_sum() ：

foreach($x_inhale as $ind => $ar){
    $res[] = array_sum(array_column($x_inhale,$ind));
}
print_r($res);

演示

Answer 2

$sum_inhale[$id]在第一个循环中是空的，这就是你不能向它添加数字的原因。 在该行之前添加：

if (!isset($sum_inhale[$id])) $sum_inhale[$id] = 0;