/**
 * @param $questions    考试考题（二维数组）
 * @param $userAnswers  考生答题（二维数组）
 * @return int
 */
function calculateScore(array $questions, array $userAnswers)
{
    $totalScore = 0; // 初始化总得分为0

    // 索引问题数组以便快速查找(题目ID)
    $indexedQuestions = array_column($questions, null, 'id'); // 使用题目ID作为键，将问题数组重新索引

    foreach ($userAnswers as $question) {
        $questionId = $question['id']; // 获取当前问题的ID
        // 检查问题是否存在于问题数组中
        if (isset($indexedQuestions[$questionId])) {
            $questionData = $indexedQuestions[$questionId]; // 获取当前问题的数据
            // 检查用户的答案是否与问题答案匹配
            if (is_array($questionData['answers']) && is_array($question['answers'])) {
                // 如果问题和用户的答案都是数组
                if (empty(array_diff($questionData['answers'], $question['answers']))) {
                    // 如果用户的答案和问题答案没有差异
                    $totalScore += $questionData['score']; // 将当前问题的得分加到总得分中
                }
            } else {
                if ($questionData['answers'] == $question['answers']) {
                    // 如果问题和用户的答案都是字符串，并且相等
                    $totalScore += $questionData['score']; // 将当前问题的得分加到总得分中
                }
            }
        }
    }

    return $totalScore; // 返回总得分
}

• 使用示例

    public function test1()
    {
        //问题答案分数
        $a = array(
            array(
                "id" => 1,//题目id
                "topic" => "选择题1",
                "answers" => "a,b",
                "score" => 10
            ),
            array(
                "id" => 2,//题目id
                "topic" => "选择题2",
                "answers" => "b",
                "score" => 10
            ),
            array(
                "id" => 3,
                "topic" => "选择题3",
                "answers" => "a",
                "score" => 10
            ),
            array(
                "id" => 4,
                "topic" => "选择题4",
                "answers" => "c",
                "score" => 10
            )
        );
        
        //用户答题
        $b = array(
            array(
                "id" => 1,//题目id
                "topic" => "选择题1",
                "answers" => "a,b",
            ),
            array(
                "id" => 2,//题目id
                "topic" => "选择题2",
                "answers" => "c",
            ),
            array(
                "id" => 3,
                "topic" => "选择题3",
                "answers" => "a",
            ),
            array(
                "id" => 4,
                "topic" => "选择题4",
                "answers" => "",
            )
        );

        $score = calculateScore($a, $b);
        echo "考试分数：" . $score;
    }

• 示例2（answers数组）

    public function test2()
    {
        $a = array(
            array(
                "id" => 1,
                "topic" => "选择题1",
                "answers" => array("a", "b"),
                "score" => 10
            ),
            array(
                "id" => 2,
                "topic" => "选择题2",
                "answers" => array("b"),
                "score" => 10
            ),
            array(
                "id" => 3,
                "topic" => "选择题3",
                "answers" => array("a"),
                "score" => 10
            ),
            array(
                "id" => 4,
                "topic" => "选择题4",
                "answers" => array("c"),
                "score" => 10
            )
        );

        $b = array(
            array(
                "id" => 1,
                "topic" => "选择题1",
                "answers" => array("a", "b"),
            ),
            array(
                "id" => 2,
                "topic" => "选择题2",
                "answers" => array("c"),
            ),
            array(
                "id" => 3,
                "topic" => "选择题3",
                "answers" => array("d"),
            ),
            array(
                "id" => 4,
                "topic" => "选择题4",
                "answers" => array("c"),
            )
        );


        // 调用函数计算得分
        $score = calculateScore($a, $b);
        echo "得分：" . $score;
    }