Question

我是Java新手......我有一个正在讨论方法的任务。出于某种原因，当我调用我的方法并将数据传回我的主要内容时，所有内容都是“-Infinity”或“0”。我一直试图解决这个问题两天，我似乎无法找到合适的解决方案。

我只包括作业第一部分的代码，因为我觉得无论我犯了什么错误......我在整个作业中都是这样做的。因此，如果有人可以帮助我完成这一部分，那么我也希望能够纠正我的其他问题。

第一种方法返回：-Infinity，但是当我将代码分开并在不使用方法的情况下运行它时...我得到11.8，这是正确的。

非常感谢任何帮助！

/*  
 * Anthony Vincenzo Laginess  
 * CIT 130  
 * Oct. 12th, 2016  
 * HMW 07 - Methods  
 * Time Needed:   
 */

package cit130hmw07_laginess;
    import java.util.Scanner;
public class CIT130HMW07_Laginess {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

//*************************************************         
//****************** Method 1 *********************         
//*************************************************         
//This method calculates body fat. It takes your gender as a parameter         
//and outputs your bodyfat. 

System.out.println("Please enter your gender...");
String gender = input.nextLine();
System.out.println("Please enter your weight: ");
int bodyWeight = input.nextInt();
System.out.println("Please enter your waist measurement: ");
int waistSize = input.nextInt();

  if(gender.equalsIgnoreCase("male")) {                                    
       bodyFatMale(bodyWeight, waistSize);
       double bodyFatPercentage = bodyFatMale(bodyWeight, waistSize);                                                       
       System.out.println("Your body fat is: " + bodyFatPercentage);   }

  else if(gender.equalsIgnoreCase("female"))         {                 
      System.out.println("Please enter your waist size: ");             
      int waist = input.nextInt();             
      System.out.println("Please enter your hip size: ");             
      int hips = input.nextInt();             
      System.out.println("Please enter your forearm size: ");             
      int forearms = input.nextInt();                                             

      bodyFatFemale(bodyWeight, waistSize, waist, hips, forearms);                   
      double answer = bodyFatFemale(bodyWeight, waistSize, waist, hips,     
      forearms);             

      System.out.println("Your body fat is: " + answer);         } 

      else 
         //enter an error message 

}//main

//METHOD 1: Bodyfat calculations     
public static double bodyFatMale(int bodyWeight, int waistSize)     {                     

    int weight = 0;         
    int waist = 0;         
    double A1;         
    double A2;         
    double B;         
    double actualBodyFat;         
    double bodyFatPercentage;                          
    A1 = (weight * 1.082) + 94.42;             
    A2 = waist * 4.15;             
    B = A1 - A2;             
    actualBodyFat = weight - B;             
    bodyFatPercentage = actualBodyFat * 100 / weight;                          

    return bodyFatPercentage;      }

 public static double bodyFatFemale(int bodyWeight, double wristSize, double waistSize, double hipSize, double forearmSize)     {         
    int weight = 0;         
    double wrist = 0;         
    double waist = 0;         
    double hips = 0;         
    double forearms = 0;         
    double A1, A2, A3, A4, A5, B;         
    double actualBodyFat;         
    double bodyFatPercentage;                               

      A1 = (weight * .732) + 8.987;             
      A2 = wrist / 3.14;             
      A3 = waist * 0.157;             
      A4 = hips * 0.249;             
      A5 = forearms * 0.434;             
      B = A1 + A2 - A3 - A4 + A5;             
      actualBodyFat = weight - B;             
      bodyFatPercentage = actualBodyFat * 100 / weight;                           

      return bodyFatPercentage;               }
}//class

Answer 1

在每个方法中，您将所有变量设置为0，因此方法内的计算将使用0执行。相反，您需要将变量分配给您作为参数传入的值。

所以而不是

int weight = 0;

试

int weight = bodyWeight;

Answer 2

提示：在bodyFat方法中，您有两个体重和腰围尺寸的变量。你使用的是错误的;即你已经初始化为ero的那个。你应该只有一个。

Answer 3

您实际上并未在计算中使用方法参数。

这是第一种方法的固定版本：

//METHOD 1: Bodyfat calculations     
public static double bodyFatMale(int bodyWeight, int waistSize) {                          
    double A1;         
    double A2;         
    double B;         
    double actualBodyFat;         
    double bodyFatPercentage;                          
    A1 = (bodyWeight* 1.082) + 94.42;             
    A2 = waistSize* 4.15;             
    B = A1 - A2;             
    actualBodyFat = bodyWeight- B;             
    bodyFatPercentage = actualBodyFat * 100 / bodyWeight;                          

    return bodyFatPercentage;
}

Answer 4

public static double bodyFatMale(int bodyWeight, int waistSize) {                     

    int weight = 0; // Introducing `0` into all calculations
    .....
    A1 = (weight * 1.082) + 94.42;   // Should be `bodyWeight`?      
    A2 = waist * 4.15;   // Should be `bodyWeight`? 
    B = A1 - A2;             
    actualBodyFat = weight - B;   // Should be `bodyWeight`?
    bodyFatPercentage = actualBodyFat * 100 / weight;   // Should be `bodyWeight`?

Java调用方法并返回数据

4 个答案: