Question

所以我正在制作一个BMI计算器，为用户提供英制和公制之间的选项。但是，无论何时计算英制bmi，它都会返回0.我非常确定这与未保存的值有关。

    import java.util.Scanner;

public class BMICalculator {

public static double lbWeight = 0;
public static double inchHeight = 0;
public static double kgWeight = 0;
public static double mHeight = 0;
public static double imperialBMI = 0;
public static double metricBMI = 0;
public static String userName;

public static void programIntroduction()
{
    System.out.print("Welcome to the BMI Calculator, please enter your name:");
    Scanner scannerName = new Scanner(System.in);
    userName = scannerName.nextLine();
}

public static void getLBWeight()
{
    System.out.print("Please enter your weight from 22 to 660 LB:");
    Scanner scannerWeight = new Scanner(System.in);
    lbWeight = scannerWeight.nextDouble();

    for (;lbWeight<22;)
    {
        System.out.println("Please enter a valid weight:");
        Scanner scannerWeight2 = new Scanner(System.in);
        lbWeight = scannerWeight2.nextDouble();
    }

    for (;lbWeight>660;)
    {
        System.out.println("Please enter a valid weight:");
        Scanner scannerWeight2 = new Scanner(System.in);
        lbWeight = scannerWeight2.nextDouble();
    }
}

public static void getInchHeight()
{
    System.out.print("Please enter your height from 20 to 120 inches:");
    Scanner scannerHeight = new Scanner(System.in);
    inchHeight = scannerHeight.nextDouble();

    for (;inchHeight<20;)
    {
        System.out.println("Please enter a valid height:");
        Scanner scannerHeight2 = new Scanner(System.in);
        inchHeight = scannerHeight2.nextDouble();
    }

    for (;inchHeight>120;)
    {
        System.out.println("Please enter a valid height:");
        Scanner scannerHeight2 = new Scanner(System.in);
        inchHeight = scannerHeight2.nextDouble();
    }

}

public static void getKGWeight()
{
    System.out.print("Please enter your weight from 10 to 300 KG:");
    Scanner scannerWeightKG = new Scanner(System.in);
    kgWeight = scannerWeightKG.nextInt();

    for (;kgWeight<10;)
    {
        System.out.println("Please enter a valid weight:");
        Scanner scannerWeight2 = new Scanner(System.in);
        kgWeight = scannerWeight2.nextInt();
    }

    for (;kgWeight>300;)
    {
        System.out.println("Please enter a valid weight:");
        Scanner scannerWeight2 = new Scanner(System.in);
        kgWeight = scannerWeight2.nextInt();
    }
}

public static void getMHeight()
{
    System.out.print("Please enter your height from .5 to 3 M:");
    Scanner scannerHeightM = new Scanner(System.in);
    mHeight = scannerHeightM.nextInt();

    for (;mHeight<.5;)
    {
        System.out.println("Please enter a valid weight:");
        Scanner scannerHeight2 = new Scanner(System.in);
        mHeight = scannerHeight2.nextInt();
    }

    for (;mHeight>3;)
    {
        System.out.println("Please enter a valid weight:");
        Scanner scannerHeight2 = new Scanner(System.in);
        mHeight = scannerHeight2.nextInt();
    }
}

public static void ImperialBMI()
{
    imperialBMI = (lbWeight*703)/(inchHeight*inchHeight);   
}

public static void MetricBMI()
{
    metricBMI = (kgWeight)/(mHeight*mHeight);

}

public static void main(String[] args) 
{
    programIntroduction();
    System.out.println("Please type 1 for imperial mode or 2 for metric mode:");
    Scanner scanner = new Scanner(System.in);
    int userInput = scanner.nextInt();
    if (userInput == 1)
    {
        getLBWeight();
        getInchHeight();
        System.out.println(imperialBMI);
    }
    if (userInput == 2)
    {
        getKGWeight();
        getMHeight();
        System.out.println(metricBMI);
    }

}

}

Answer 1

您已将imperialBMI和metricBMI初始化为0，但您从未调用计算其值的方法。在输出相应的变量之前，请先调用MetricBMI()或ImperialBMI()。

BMI计算器每次都返回0

1 个答案: