如何在多键数组中找到最大值？

function findMaxValue($multiKeyArray) {
    $maxValue = null;
    
    foreach ($multiKeyArray as $keys => $value) {
        if ($maxValue === null || $value > $maxValue) {
            $maxValue = $value;
        }
    }
    
    return $maxValue;
}

// 示例用法
$multiKeyArray = [
    ['key1', 'key2', 'key3'] => 10,
    ['key1', 'key2', 'key4'] => 20,
    ['key1', 'key2', 'key5'] => 15,
];

$maxValue = findMaxValue($multiKeyArray);
echo "最大值为: " . $maxValue;