java - java不在2个类中打印？

Question

我有两个班级，当我运行演示程序时，它不会打印出另外两个“华氏到摄氏”它会打印前 3 个而不是第二组。所以程序将运行，我只是无法将所有华氏温度都打印到摄氏温度。我不知道我的代码中缺少什么以打印出其他信息。谢谢！

第1部分：

import java.util.*;

public class   Thermometer//create a class temperature
{
    //declare private variable to class Thermometer
    private double temperature; // declare the two instance variables
    private char tempType;

    
    //*** Create FOUR constructor method****
    
    public Thermometer() // sets default value to 'C' tempType and 0 degrees temperature
    {
        
        temperature = 0; // set to zero degrees celsius
        tempType = 'C';
    }
    public Thermometer(char tempType, double temperature)// create a constructor for the instance variable named scale
    {
        this.temperature = temperature;
        this.tempType = tempType;
        temperature = 0;  // assign zero degrees if no value is specified
    }
    
    /********** (1) ****** create TWO accessor methods ****/
    
    public double getCelsius() //create first accesor method to convert F to C degrees  called getCelsius
    {
        if (tempType == 'C')//if tempType is C just return temperature because this method returns Celcius
        {
            return temperature;
        }
        else  //or if tempType is F  do the following calculations to convert Celcius to Fahrenheit and return those results
        {
        // Round to the nearest tenth of a degree and convert F to C
        return ((double) (Math.round((5 * (temperature - 32.0) / 9.0) * 10.0)) / 10); //formula for C to F
        }
    }
    public double getFahrenheit()  //create second accesor method to convert C to F degrees 
    {
        if (tempType == 'F')//if tempType is F just return temperature because this method returns Fahrenheit
        {
            return temperature;
        }
        else//or if tempType is C  do the following calculations to convert Farhenheit to Celsius and return those results
        {
            // Round to the nearest tenth of a degree and convert F to C
        return (Math.round((9 * (temperature / 5) + 32) * 10) / 10);
                                        
        }
    }
    /********** (2) **********/
    // Create THREE mutator methods.
    
    public void setTemperature(double temperature) //create FIRST mutator to set temperature class variable
    {
        this.temperature = temperature;
    }
    
    public void setTempType(char tempType) // create SECOND mutator to set the tempType class variable
    {
        this.tempType = tempType;
    }
    
    public void setTemperatureScale(double temperature, char tempType) // create THIRD mutator  to get temperature class variable and get tempType class variable
    {
        this.temperature = temperature;
        this.tempType = tempType;
    }
    
    /*********** (3) *********/
    // Create three comparison methods.
    
    public boolean equals(Object obj)// create an equals method to test if two temperatures are equal--- (Object type, obj) coming through as parameters
                           
    {
        if (obj instanceof Thermometer)
        {
            Thermometer t = (Thermometer) obj;  //create instance of Thermometer 't' to hold the other object to compare both if (equal to)
            return getCelsius() == t.getCelsius();//return true if first object == second object
        }
        return false; //return false if first object not equal second object
    }
    public boolean lessthan(Object obj)// create less  than method to test if one temperatures is less than other --- (Object type, object) coming through as parameter    
    {
        if (obj instanceof Thermometer) 
        {
            Thermometer t = (Thermometer) obj;//return true if first object less than second object
            return getCelsius() > t.getCelsius();
        }
        return false; //return false if greater than
    }
    public boolean greaterthan(Object obj) // create greater  than method to test if one temperatures is  greater thant other --- (Object type, object) coming through as parameter
                          
    {
        if (obj instanceof Thermometer)
        {
            Thermometer t = (Thermometer) obj;
            return getCelsius() < t.getCelsius();//return true if first object greater than second object
        }
        return false; //return true if less than
    }
    /************ (4) ***********/
    
    public String toString()  // create an appropriate toString method
    {
    if (tempType == 'C')//if tempType is C
    {
    return String.format("%.1f degrees C = %.1f degrees F", temperature, getFahrenheit());// return the getFahrenheit method  (print it to console)
    // prints degrees in fahrenheit = degrees in celsius      
    }
       else
       {
 return String.format("%.1f degrees F = %.1f degrees C", temperature, getCelsius());//p return the getCelsius  method (print it to console)
    // prints degrees in celsius = degrees in fahrenheit  
       }
    }
}

第2部分：

import java.util.*;
import javax.swing.*;

public class ThermometerDemo 
{
    // Create a main method to run the program.
    public static void main(String[] args)
    {
       System.out.println("Celsius to Fahrenheit:");
        
      // Create an object named CtoF_firstObj.
        Thermometer CtoF_firstObj = new Thermometer();
        CtoF_firstObj.setTemperature(0.00);
        CtoF_firstObj.setTempType('C');
        System.out.println(CtoF_firstObj.toString());

        
  // Create an object named CtoF_secondObj.
        Thermometer CtoF_secondObj = new Thermometer('C', 0);
        CtoF_secondObj.setTemperature(-40);
        System.out.println(CtoF_secondObj.toString());
        
        
  // Create an object named CtoF_thirdObj.
        Thermometer CtoF_thirdObj = new Thermometer('C',100);
        System.out.println(CtoF_thirdObj.toString());
        
        
  // Create an object named FtoC_fourthObj.
        System.out.println("\nFahrenheit to Celsius:");
        Thermometer FtoC_fourthObj = new Thermometer();
        FtoC_fourthObj.setTemperatureScale(56.00, 'F');
        System.out.println(FtoC_fourthObj.toString());
        
        
  // Display Comparision

System.out.println("\nComparision:");

System.out.println("CtoF_firstObj < CtoF_secondObj: " + CtoF_firstObj.lessthan(CtoF_secondObj));
System.out.println("CtoF_secondObj = CtoF_thirdObj: " + CtoF_firstObj.equals(CtoF_thirdObj));
System.out.println("CtoF_thirdObj > FtoC_fourthObj: "+CtoF_thirdObj.greaterthan(FtoC_fourthObj));       
    }   
}

标签： javaclass

Answer 1

你的lessthan和greaterthan逻辑是相反的。修复它们如下：

lessthan

getCelsius() < t.getCelsius()

greaterthan

getCelsius() > t.getCelsius()

以下是输出：

Celsius to Fahrenheit:

0.0 degrees C = 32.0 degrees F

-40.0 degrees C = -40.0 degrees F

100.0 degrees C = 212.0 degrees F

Fahrenheit to Celsius:

56.0 degrees F = 13.3 degrees C

Comparision:   

CtoF_firstObj < CtoF_secondObj: false  
 
CtoF_secondObj= CtoF_thirdObj: false  
 
CtoF_thirdObj > FtoC_fourthObj: true