在关联数组中查找最高值

Question

有没有一种相对简单的方法可以找到关联数组中每个键的最高值？

Array(
    0 => Array(
        "avgtime"   => 19.75,
        "bounces"   => 3,
        "pageviews" => 14,
        "visitors"  => 4
    )
    1 => Array(
        "avgtime"   => 1.125,
        "bounces"   => 7,
        "pageviews" => 9,
        "visitors"  => 8
    )
    2 => Array(
        "avgtime"   => 111,
        "bounces"   => 18,
        "pageviews" => 32,
        "visitors"  => 20
    )
    3 => Array(
        "avgtime"   => 6.9375,
        "bounces"   => 14,
        "pageviews" => 18,
        "visitors"  => 10   
    )
    4 => Array(
        "avgtime"   => 191,
        "bounces"   => 11,
        "pageviews" => 57,
        "visitors"  => 24
    )
);

我想创建一个数组，为每个键保存最高值，这样最终结果会是

Array(
    "avgtime"   => 191,
    "bounces"   => 18,
    "pageviews" => 57,
    "visitors"  => 24
);

Answer 1

遍历数组并存储每个关键的最大值

$temp = array();
foreach ($data as $item) {
    foreach ($item as $key => $value) {
        $temp[$key] = max(
                isset($temp[$key]) ? $temp[$key] : $value,
                $value);
    }
}

Answer 2

function maxRecursive(array $arr) {
    $maxArray = array();
    array_walk_recursive($arr, function($val, $key) use(&$maxArray){
        if( ( !$maxArray[$key] ) || $maxArray[$key] < $val ){
            $maxArray[$key] = $val;
        }
    });
    return $maxArray;
}