在我的java項目上獲得NaN

我剛開始學習java 2個月前，我有一個項目可以創建一個可以使用英制系統和公制系統的BMI計算器。我創造了它，但是我得到了Nan作爲BMI的答案。我沒有在任何語法錯誤，我不明白爲什麼我收到NaN`在我的java項目上獲得NaN

import java.util.Scanner; 
import java.util.InputMismatchException; 


public class BmiCalculator 
{ 
       Scanner input = new Scanner(System.in);     
       // ConvertSystem convert = new ConvertSystem(); 


    String name; 
    double height; 
    double stone; 
    double pound; 
    double feet; 
    double inch; 
    double kg; 
    double meters; 
    double wheight; 
    double BMI; 
    int MetricOrImperial ; 



    public void getIntro() 
    { 
     System.out.println("Welcome to the Body Mass Index Calculator"); 

     System.out.println("Please enter your name:"); 
     name = input.nextLine(); 
     System.out.printf("Hello %s !\n", name); 
    } 
    public void metricOrImperial() 
    {  boolean continueLoop = true;    
    do 
    { 
     try 
     {  
     System.out.println("Please choose which measurement system you want to use; \n "); 
     System.out.println("For Imperial type number 1:\nFor Metric type number 2 \n"); 
     MetricOrImperial = input.nextInt(); 

     continueLoop = false; 
     }// end try 
     catch (InputMismatchException inputMismatchException) 
     { 
     System.err.printf("\nException: %s\n",inputMismatchException); 
      input.nextLine(); 
      System.out.println 
       ("\nYou must enter number 1 or 2\n Please try again");  
     }// end catch 
     }// end do 
     while (continueLoop); 

    } // end imperialOrMetric 
    public void getImperial() 
    { boolean continueLoop = true; 
     do{ 
      try{ 
    if (MetricOrImperial == 1) 
     { 
      System.out.println("Please enter your wheight in Stones: "); 
      stone = input.nextDouble(); 
      System.out.println("Enter your wheight in Pounds: "); 
      pound = input.nextDouble(); 
      System.out.println("Please enter your height in feets: "); 
      feet = input.nextDouble(); 
      System.out.println("Enter your height in inch: "); 
      inch = input.nextDouble(); 
     } 
     continueLoop= false; 
     } // end try 
     catch (InputMismatchException inputMismatchException) 
     { 
     System.err.printf("\nException: %s\n",inputMismatchException); 
      input.nextLine(); 
      System.out.println 
       ("\nPlease enter only number\n Try again!");  
     }// end catch 
     }while(continueLoop); 
    }  
    public void getMetric() 
    { boolean continueLoop = true; 
     do{ 
      try{ 
    if (MetricOrImperial == 2) 
     { 
      System.out.println("Please enter your wheight in Kg "); 
      kg = input.nextDouble(); 
      System.out.println("Please enter your height in Meters: "); 
      meters = input.nextDouble(); 
     } 
     continueLoop= false; 
     } // end try 
     catch (InputMismatchException inputMismatchException) 
     { 
     System.err.printf("\nException: %s\n",inputMismatchException); 
      input.nextLine(); 
      System.out.println 
       ("\nPlease enter only number\n Try again!");  
     }// end catch 
     }while(continueLoop); 
    }// end getMetric 
    public void convertToMetric() 
    { 
     if (MetricOrImperial == 1) 
     { 
     wheight = (stone * 6.3502) + (pound * 0.4536); 
     height = (feet * 0.3048) + (inch * 0.0254); 
     } 
     else 
     { 
     wheight = kg; 
     height = meters; 
     } 
    } 
    public void getBmi() 
    { 


     BMI = wheight/(height* height) ; 
     System.out.println(BMI); 



    } 
} // endBMI calculator

import java.util.*; 
 

 

 
public class BmiCalculatorTest extends BmiCalculator { 
 
    public static void main(String[] args) 
 
    { 
 
     BmiCalculator bmi = new BmiCalculator(); 
 
     bmi.getIntro(); 
 
     bmi.metricOrImperial(); 
 
     bmi.getImperial(); 
 
     bmi.getMetric(); 
 
     bmi.getBmi();

來源

2016-12-14 Teo

我敢打賭你的避風港」 t _actually_初始化高度。 –

您可以添加您的主要方法或顯示您調用方法的順序和您輸入的輸入。 – develop1

你不要調用'bmi.convertToMetric（）;'。（它是_weight_！） –

的原因，它不工作是你從未呼籲bmi.convertToMetric()來計算身高。

如果你運行該代碼的代碼工作

public static void main(String[] args) 
{ 
    BmiCalculator bmi = new BmiCalculator(); 
    bmi.getIntro(); 
    bmi.metricOrImperial(); 
    bmi.getImperial(); 
    bmi.getMetric(); 
    bmi.convertToMetric(); //Added call to converToMetric to calculate height 
    bmi.getBmi(); 
}

你有楠原因是高度設置爲0.0，所以你試着將0.0/0.0在getBmi()

來源

2016-12-14 00:27:48 develop1

在我的java項目上獲得NaN

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