如何获取特定Array索引值的总和

I am reading data from file and displaying array like below code :

  if (($fp = fopen("test.txt", "r")) !== FALSE) {       
    $count = 0;
    while(($row = fgetcsv($fp)) !== FALSE)
    {


        $row = explode("|",$row[0]);
        foreach($row as &$el)
        {
            $el=trim($el);

        }
        $count++;
                $tot = array_sum(array_column($row,2));
        echo "<pre>";print_r($row); 
                if($count>3)
        {
            break;  
        }
      echo "Coumt :".$tot;  
    }

          echo "Coumt :".$tot;
    fclose($fp);
}

Test.txt file data :

005-4410040             |BIRM|      0 
005-4410040             |CHI |  
450 005-4410040         |CIN |    144

I want total sum of 2nd index of the array it means 320 + 450 + 144 in seperate varriable.

How can i achieve this ? Already tried array_column but its not working.

Update What i have tried :

$sum = array_sum(array_column($row,$row['2']));

You should be able to achieve that using array_column() and array_sum() like this

$row = [
        ['005-4410040','BIRM',1],
        ['005-4410040','CHI',2],
        ['005-4410040','CIN',3]
    ];

$tot = array_sum(array_column($row, 2));

RESULT

6

After code added to the question:

You are not understanding fgetcsv() correctly, it gets one line at a time. So each call to fgetcsv return one line from the file which you explode into $row

All you need to do is accumulate $row[2] as you process over the lines of the file.

if (($fp = fopen("test.txt", "r")) !== FALSE) {       
    $count = 0;
    $tot = 0;

    while(($row = fgetcsv($fp)) !== FALSE)
    {
        $row = explode("|",$row[0]);
        $count++;
        // I see one line with no value so to be safe
        $tot += $row[2] != '' ? $row[2] : 0;

        if($count>3) {
            break;  
        }
        echo "Coumt : $tot";  
    }

    echo "Coumt : $tot";
    fclose($fp);
}

You are calling wrong sequence

$arr=array(array
(
     0  => "005-4410040",
     1  => "BIRM",
     2  => 320
),
array
(
     0  => "005-4410040",
     1  => "CHI",
     2  => 450
),
array
(
     0  => "005-4410040",
     1  => "CIN",
     2  => 144
));
echo (array_sum(array_column($arr, 2)));