Question

我有一个名为correctAnswer的数组，它有10个值。每个值都是A，B，C或D.

然后我有一个名为studentAnswers的二维数组，它有3行10列。我想创建一个方法来检查每列的匹配数。

例如：

正确答案：[B，C，A，A，B，A，C，D，A，C]

学生1结果：C，D，C，D，B，D，C，C，A，B 学生2结果：A，A，B，C，D，C，B，B，D，D 学生3结果：A，C，C，C，B，C，A，A，A，A

然后它应该打印：

答案1：0 答案2：1 等等......直到它达到10，因为数组中有10个值为correctAnswers

到目前为止，这是我的代码：

private char[] correctAnswer = { 'B', 'C', 'A', 'A', 'B', 'A', 'C', 'D', 'A', 'C' };

private char[][] studentAnswers;

// constructor
    public MultipleChoice(int numberOfStudents) {
    studentAnswers = new char[numberOfStudents][10];
    for (int i = 0; i < studentAnswers.length; i++) {
        for (int j = 0; j < studentAnswers[i].length; j++) {
            int tal = (int) (Math.random() * 4);
            char c = (char) (tal + 'A');
            studentAnswers[i][j] = c;
        }
    }
}

// my method
public void printCorrectAnswerPrQuestion() {
    for (int i = 0; i < correctAnswer.length; i++) {

        System.out.print("number of correct answers to question number " + correctAnswer[i + 1] + ": ");
        int correctAnswers= 0;

        for (int j = 0; j < correctAnswer.length; j++) {
            if (correctAnswer[j] == studentAnswers[i][j]) {
                correctAnswers= correctAnswers+ 1;
            }
        }
        System.out.print(correctAnswers);
        System.out.println();
    }
}

Answer 1

外部for循环i < correctAnswer.length上的条件错误。它必须是studentAnswers.length。这将为每个学生提供正确答案的数量。

如果您想知道正确回答问题的学生人数

for (int i = 0; i < correctAnswer.length; i++) {
    int correctAnswers = 0;
    System.out.print("number of correct answers to question number " + i + ": ");

    for (int j = 0; j < studentAnswers.length; j++) {
        if (correctAnswer[i] == studentAnswers[j][i]) {
            correctAnswers = correctAnswers + 1;
        }
    }
    System.out.println(correctAnswers);
}

如何获得二维数组中每列的相等匹配数？

1 个答案: