使用PHP查找和更新多维数组值

Question

我找不到这个线程的合适标题（帮帮我）。我不能描述这个问题，所以这里是我的问题的例子。

我的数组：

Array ( [0] => Array ( [answer] => a [score] => 3 )
[1] => Array ([answer] => b [score] => 4 ) 
[2] => Array ( [answer] => h [score] => 3) 
[3] => Array ( [answer] => a [score] => 4 ))
...

我想得到这样的输出：

Array ( [0] => Array ( [answer] => a [score] => 7 )
[1] => Array ([answer] => b [score] => 4 ) 
[2] => Array ( [answer] => h [score] => 3))
...

您可以在索引键0中看到分数子键的更改。这是因为索引键0和3的应答子键中有两个值“a”。由于两者的总和（34），分数改为7分。我真的不知道该怎么做，对不起我的英语，谢谢你的帮助。请随意评论。：）

Answer 1

我想到了使用临时数组：

/* Current array */
$array = array(
    array("answer" => "a", "score" => 3),
    array("answer" => "b", "score" => 4),
    array("answer" => "h", "score" => 3),
    array("answer" => "a", "score" => 4)
);

/* Using a temporary array */
$tmp_array = array();
foreach($array as $subarray){
    if(array_key_exists($subarray["answer"], $tmp_array)){
        $tmp_array[$subarray["answer"]] += $subarray["score"];
    }else{
        $tmp_array[$subarray["answer"]] = $subarray["score"];
    }
}

/* Creating a new formatted array */
$new_array = array();
foreach($tmp_array as $key => $value){
    $new_array[] = array("answer" => $key, "score" => $value);
}

print_r($new_array);

Answer 2

检查此答案，不使用循环：

$arr  = array ( array ( 'answer' => 'a', 'score' => 3 ),
                array ( 'answer' => 'b', 'score' => 4 ), 
                array ( 'answer' => 'h', 'score' => 3), 
                array ( 'answer' => 'a', 'score' => 4 ));

$t = array_reduce($arr, function($result, $item) {
        if(array_key_exists($item['answer'],$result)){
           $result[$item['answer']]    = array('answer' => $item['answer'], 'score' => $item['score']+$result[$item['answer']]['score']);
        }
        else{
           $result[$item['answer']]    = array('answer' => $item['answer'], 'score' => $item['score']);
        }
    return $result;
},array()); 

echo "<pre>";
print_r($t);

输出：

Array
(
    [a] => Array
        (
            [answer] => a
            [score] => 7
        )

    [b] => Array
        (
            [answer] => b
            [score] => 4
        )

    [h] => Array
        (
            [answer] => h
            [score] => 3
        )

)

Answer 3

$merged = array();

foreach ($array as $answer) {
    if (isset($merged[$answer['answer']])) {
        $merged[$answer['answer']]['score'] += $answer['score'];
    } else {
        $merged[$answer['answer']] = $answer;
    }
}

var_dump($merged);