返回方法重载

Question

我是Java的新手,我自己也在学习.我尝试重载方法时遇到了麻烦.这是代码

 public static void main(String[] args) {
        calculateScore();
        calculateScore(500);
        calculateScore("Duy", 600);
        calcFeetAndInchesToCentimetres(100, 3.5);
        calcFeetAndInchesToCentimetres(100*12 + 3.5);
    }

 public static double calcFeetAndInchesToCentimetres(double feet, double inches) {
        if (feet >= 0 && inches >= 0 && inches <= 12) {
            double footToInches = feet * 12;
            double centimetres = (inches + footToInches) * 2.54;
            System.out.println("The value in centimetres is " + centimetres + " cm.");
            return centimetres;
        } else {
            return -1;
        }
    }

    public static double calcFeetAndInchesToCentimetres(double inches) {
        if (inches >= 0){
            double inchesToFeet = inches / 12;
            double inchesRemain = inches - (inchesToFeet * 12);
            calcFeetAndInchesToCentimetres(inchesToFeet, inchesRemain);
            return 0;
        } else {
            return -1;
        }

我的问题是当我return 0从第二种方法中取出时,调试器会说"缺少return语句".然后我试着放return calcFeetAndInchesToCentimetres(inches);,它有效,但程序运行了大约数千次.

然后我把return 0,一切都好.但是我不明白为什么我不能把它return calcFeetAndInchesToCentimetres(inches);和为什么我需要一个return语句,当上面的方法(有2个参数)有它时.如果我想在执行第二种方法时转换厘米的值(仅使用"inches"参数),我该怎么做？

我在块代码中意识到的另一件事

double inchesToFeet = inches / 12;
        double inchesRemain = inches - (inchesToFeet * 12);
        calcFeetAndInchesToCentimetres(inchesToFeet, inchesRemain);

inchesRemain将为0？但该方法效果很好.当我改变时inchesToFeet = inches % 12,它只是没有显示任何东西.为什么？

Answer 1

它应该只是:

public static double calcFeetAndInchesToCentimetres(double inches) {
    if (inches >= 0){
        double inchesToFeet = inches / 12;
        double inchesRemain = inches - (inchesToFeet * 12);
        return calcFeetAndInchesToCentimetres(inchesToFeet, inchesRemain);
    } else {
        return -1;
    }
}

你说你已经尝试了return calcFeetAndInchesToCentimetres(inches);但是这只是递归地调用你的方法而且它会永远地递归,因为没有停止条件.