Question

有谁能告诉我这段代码我做错了什么？

public class grades {
    public static void main(String[] args) {
        int[] testMarks = Marks.getMarks();
        System.out.print(grading(testMarks));

    }
    public static char[] grading(int[] testMarks) {

        char grade = '0';
        char[] grades = new char[grade];
        int value = 0;
        int n = 0;
            while (n < testMarks.length) {
                value = testMarks[n];
                if (value >= 90) {
                grade = 'A';
                }
                else if (value < 90 && value >= 75) {
                grade = 'B';
                }
                else if (value < 75 && value >= 60) {
                grade = 'C';
                }
                else if (value < 60 && value >= 50) {
                grade = 'D';
                }
                else if (value < 50 && value >= 45) {
                grade = 'E';
                }
                else {
                grade = 'F';
                }
                n =+ 1;
        }
        return grades;
    }
}

我试图根据列出的边界将testMarks数组的值作为char返回。我没有收到任何错误，但它没有显示任何内容。

干杯， EM

Answer 1

n =+ 1将是n += 1。
char[] grades = new char[grade]将为char[] grades = new char[testMarks.length]
在增加n之前，写下grades[n] = grade

Answer 2

您忘记填写成绩数组:)您需要：

grades[n] = grade;

在递增n之前

;否则grade数组将为空。除此之外，n ++可以正常工作：

public static char[] grading(int[] testMarks) {

    char grade = '0';
    char[] grades = new char[testMarks.length];
    int value = 0;
    int n = 0;
        while (n < testMarks.length) {
            value = testMarks[n];
            if (value >= 90) {
            grade = 'A';
            }
            else if (value < 90 && value >= 75) {
            grade = 'B';
            }
            else if (value < 75 && value >= 60) {
            grade = 'C';
            }
            else if (value < 60 && value >= 50) {
            grade = 'D';
            }
            else if (value < 50 && value >= 45) {
            grade = 'E';
            }
            else {
            grade = 'F';
            }
            grades[n] = grade;
            n++;
    }
    return grades;
}

Answer 3

也许你应该在你的代码中写n + = 1

Answer 4

grades数组始终为空。您需要在返回之前将grade值存储在该数组中。这样的事情应该有效：

public static char[] grading(int[] testMarks) {

    char grade = '0';
    char[] grades = new char[testMarks.length]; // initialise with an empty char array with the same length as testMarks
    int value = 0;
    int n = 0;
    while (n < testMarks.length) {
        value = testMarks[n];
        if (value >= 90) {
            grade = 'A';
        }
        else if (value < 90 && value >= 75) {
            grade = 'B';
        }
        else if (value < 75 && value >= 60) {
            grade = 'C';
        }
        else if (value < 60 && value >= 50) {
            grade = 'D';
        }
        else if (value < 50 && value >= 45) {
            grade = 'E';
        }
        else {
            grade = 'F';
        }
        grades[n] = grade; // store the grade in the grades array
        n += 1;
    }
    return grades;
}

通过在Java中测试int数组的值来创建char数组

4 个答案: