Question

我是Java新手并尝试制作基本的体重计算器。我的问题是我需要问问题，转换测量值然后将其传递给另一个方法，然后以单独的方法显示结果。我已在下面添加了我的代码，但每次都会返回1.0作为答案。

import java.util.Scanner;

public class calcBMI {

    public static void main(String[] args) 
    {
        Scanner keyboard = new Scanner( System.in );

        System.out.print("Enter weight in pounds: ");
        double weightInPounds = keyboard.nextDouble();
        double weightInKg = (weightInPounds / 2.2);

        System.out.print("Enter height in inches: ");
        double heightInInches = keyboard.nextDouble();
        double heightInMeters = (heightInInches / 0.254);
        double resultBMI = 1;

        displayResults(resultBMI);
    }

    public static double bodyMassIndex(double weightInKg, double 
    heightInMeters)
    {
        double resultBMI = weightInKg / Math.pow(heightInMeters, 2) * 1.375;

        return resultBMI;
    }        

    public static void displayResults(double resultBMI)
    {

        System.out.printf("The calculated body mass index was: " + resultBMI);

        System.out.println();
    }
}

更新了代码，现在正在获取; 以磅为单位输入重量：180 以英寸为单位输入高度：68 计算的体重指数为：1.1415618118905313E-5 建立成功（总时间：3秒）

import java.util.Scanner;

public class calcBMI {

    public static void main(String[] args) 
    {
        Scanner keyboard = new Scanner( System.in );

        System.out.print("Enter weight in pounds: ");
        double weightInPounds = keyboard.nextDouble();
        double weightInKg = (weightInPounds / 2.2);

        System.out.print("Enter height in inches: ");
        double heightInInches = keyboard.nextDouble();
        double heightInMeters = (heightInInches / 0.0254);


        displayResults(bodyMassIndex(weightInKg, heightInMeters));
    }

public static double bodyMassIndex(double weightInKg, double heightInMeters)
    { 
        return (weightInKg / Math.pow(heightInMeters, 2));
    }        

public static void displayResults(double resultBMI)
    {

        System.out.printf("The calculated body mass index was: " + resultBMI);

        System.out.println();
    }
}

Answer 1

您根本没有在代码中调用bodyMassIndex方法。变化

displayResults(resultBMI);

到

displayResults(bodyMassIndex(weightInKg, heightInMeters));

resultBMI等于 1 ，所以当然输出总是：

"The calculated body mass index was: 1"

完整代码：

public static void main(String[] args) {

    System.out.print("Enter weight in pounds: ");
    double weightInPounds = keyboard.nextDouble();
    double weightInKg = (weightInPounds / 2.2);

    System.out.print("Enter height in inches: ");
    double heightInInches = keyboard.nextDouble();
    double heightInMeters = (heightInInches / 0.254);        

    // You can get rid of the resultBMI variable
    displayResults(bodyMassIndex(weightInKg, heightInMeters));
}

Answer 2

你得到1.0因为你硬编码它。

改变这个：

public class Motorcycle : IVehicle
{
    #region IVehicle implementation 

    #endregion

    #region Nested Types

    public sealed class Helmet
    {
        public string Color;
        public string Size;
        public string VisorType;
        public bool RequiredByLaw;
    }

    public Helmet Helmet;
    public decimal Mileage;

    #endregion
}

要：

double resultBMI = 1;

顺便说一句，你也可以直接在方法中返回BMI， 不再需要乘以1.375 ，因为你已经在KG中提供了体重：

double resultBMI = bodyMassIndex(weightInKG, heightInMeters);

添加：

您从英寸到米的转换也是错误的。它应该是：

public static double bodyMassIndex(double weightInKg, double heightInMeters)
{
    return (weightInKg / (heightInMeters*heightInMeters));
}

基本Java，在方法

2 个答案: