对子数组中具有相同键的元素求和

Question

<?php 
$A = array(
        'A'=>array('a'=>array(
                                'v1'=>1
                                'v2'=>2
                                'v3'=>3
                                ),
                  'b'=>array(
                                'v1'=>1
                                'v2'=>2 
                                'v3'=>3                                
                                )
                   ),
        'B'=>array('a'=>array(
                                'v1'=>1
                                'v2'=>2
                                'v3'=>3
                                ),
                     'b'=>array(
                                'v1'=>1
                                'v2'=>2
                                'v3'=>3                                
                                )
                   ),
        ...
        );
=>$total= array('a'=>array(
                                'v1'=>2
                                'v2'=>4
                                'v3'=>6
                                ),
             'b'=>array(
                                'v1'=>2
                                'v2'=>4 
                                'v3'=>6  
?>

它工作，但不是一个通用的方式。

$total_av1 = $A['A']['a']['v1'] + $A['B']['a']['v1'];
$total_av2 = $A['A']['a']['v2'] + $A['B']['a']['v2'];
$total_av3 = $A['A']['a']['v3'] + $A['B']['a']['v3'];

$total_bv1 = $A['A']['b']['v1'] + $A['B']['b']['v1'];
$total_bv2 = $A['A']['b']['v2'] + $A['B']['b']['v2'];
$total_bv3 = $A['A']['b']['v3'] + $A['B']['b']['v3'];
$total = array(
                "a"=>array($total_av1,$total_av2,$total_av3),
               "b"=>array($total_bv1,$total_bv2,$total_bv3)               
               );
echo '<pre>';
print_r($A);               
print_r($total);
echo '</pre>';

Answer 1

如果你想更花哨(或者真的讨厌 foreach):

源数组:

$A = array(
        'Z'=>array('d'=>array(
                                'v1'=>10,
                                'v2'=>20,
                                'v3'=>30
                                )
                   ),
        'A'=>array('a'=>array(
                                'v1'=>1,
                                'v2'=>2,
                                'v3'=>3
                                ),
                  'b'=>array(
                                'v1'=>1,
                                'v2'=>2,
                                'v3'=>3                                
                                )
                   ),
        'B'=>array('a'=>array(
                                'v1'=>1,
                                'v2'=>2,
                                'v3'=>3
                                ),
                     'b'=>array(
                                'v1'=>1,
                                'v2'=>2,
                                'v3'=>3                                
                                )
                   ),
        'C'=>array('a'=>array(
                                'v1'=>9,
                                'v2'=>8,
                                'v3'=>7
                                ),
                     'b'=>array(
                                'v1'=>6,
                                'v2'=>5,
                                'v3'=>4                                
                                )
                   )
        );

程序:

$total=array_reduce($A,function(&$r,$v){
    array_walk($v,function($val,$key)use(&$r){
        if(!isset($r[$key])) $r[$key]=array();
        array_walk($val,function($vv,$vk)use(&$r,$key){
            if(!isset($r[$key][$vk])) $r[$key][$vk]=0;
            $r[$key][$vk]+=$vv;
        });
    });
    return $r;
},array());
print_r($total);

输出:

Array
(
    [d] => Array
        (
            [v1] => 10
            [v2] => 20
            [v3] => 30
        )
    [a] => Array
        (
            [v1] => 11
            [v2] => 12
            [v3] => 13
        )
    [b] => Array
        (
            [v1] => 8
            [v2] => 9
            [v3] => 10
        )
)

注意，我特意添加了一个不规则的$A['Z']来演示这个过程。

要求PHP>=5.3。现场演示

Answer 2

这几乎是一样的。

$a['v1'] = $A['A']['a']['v1'] + $A['B']['a']['v1'];
$a['v2'] = $A['A']['a']['v2'] + $A['B']['a']['v2'];
$a['v3'] = $A['A']['a']['v3'] + $A['B']['a']['v3'];
$b['v1'] = $A['A']['b']['v1'] + $A['B']['b']['v1'];
$b['v2'] = $A['A']['b']['v2'] + $A['B']['b']['v2'];
$b['v3'] = $A['A']['b']['v3'] + $A['B']['b']['v3'];
$total= array('a'=> $a, 'b'=> $b);
echo "Not so generic <pre>";
print_r($total);
echo "</pre>";

要使其泛型，需要嵌套一些正确使用键的循环。

for ($i = 1; $i < count($A['A']['a']) + 1; $i++) {
    $total2['a']['v'.$i] = $A['A']['a']['v'.$i] + $A['B']['a']['v'.$i];
    $total2['b']['v'.$i] = $A['A']['b']['v'.$i] + $A['B']['b']['v'.$i];
}
echo "Sort of generic <pre>";
print_r($total2);
echo "</pre>";