Question

In java code:

Write a Temperature class that has two private instance variables:

• degrees: a double that holds the temperature value • scale: a character either ‘C’ for Celsius or ‘F’ for Fahrenheit (either in uppercase or lowercase)

The class should have (1) four constructor methods: one for each instance variable (assume zero degrees if no value is specified and assume Celsius if no scale is specified), one with two parameters for the two instance variables, and a no-argument constructor (set to zero degrees Celsius);

(2) two getter methods to return the temperature, one to return the degrees Celsius, the other to return the degrees Fahrenheit – use the following formulas to write the two methods, and round to the nearest tenth of a degree:

degreesC = (degreesF – 32) *5 /9 degreesF = (degreesC *9 /5) + 32

(3) three setter methods, one to set the value, one to set the scale (‘F’, ‘f’, ‘C’, or ‘c’, if any other invalid character is given, terminate your program), and one to set both;

(4) three comparison methods, an equals method to test whether two temperatures are equal, one method to test whether one temperature is greater than another, and one method to test whether one temperature is less than another (note that a Celsius temperature can be equal to a Fahrenheit temperature as indicated by the above formulas). Write a driver program in TemperatureTest that tests each of the constructors, getters, setters, and include at least one true and one false case for each of the comparison methods.

Answer 1

//Temperature.java

class Temperature
{
private
double degrees;
char scale;
//constructors
public
Temperature()
{
degrees=0;
scale='c';
}
Temperature(double deg)
{
degrees=deg;
scale='c';
}
Temperature(char ch)
{
degrees=0;
scale=ch;
}
Temperature(double deg, char ch)
{
degrees=deg;
scale=ch;
}
//getter methods
double getCelcius()
{
return ((degrees-32) * (5/9));
  
}
double getFahrenheit()
{

return (degrees*(9/5)+32);

}
//setter methods
void setDegrees(double deg)
{degrees=deg;
  
}
void setScale(char ch)
{
if(ch=='F'||ch=='f'||ch=='c'||ch=='C')
scale=ch;
else
System.exit(0);
}
void setBoth(double deg, char ch)
{degrees=deg;
scale=ch;
}
//comparision methods
boolean equals(Temperature t)
{
  
double temp;
if(this.degrees==t.degrees)
return true;
  
else if(this.scale=='c'||this.scale=='C' && t.scale=='F'||t.scale=='f')
{
temp=t.getCelcius();
if(this.degrees==temp)
return true;
else
return false;
}
else if(this.scale=='F'||this.scale=='f' && t.scale=='c'||t.scale=='C')
{
temp=t.getFahrenheit();
if(this.degrees==temp)
return true;
else
return false;
}
else
return false;
  
  
}
  
boolean lessThan(Temperature t)
  
{
double temp;
if(this.scale=='c'||this.scale=='C' && t.scale=='F'||t.scale=='f')
{
temp=t.getCelcius();
if(this.degrees<=temp)
return true;
else
return false;
}
else if(this.scale=='F'||this.scale=='f' && t.scale=='c'||t.scale=='C')
{
temp=t.getFahrenheit();
if(this.degrees<=temp)
return true;
else
return false;
}
else
{
if(this.degrees<=t.degrees)
return true;
else
return false;
}
}
boolean greaterThan(Temperature t)
  
{
double temp;
if(this.scale=='c'||this.scale=='C' && t.scale=='F'||t.scale=='f')
{
temp=t.getCelcius();
if(this.degrees>=temp)
return true;
else
return false;
}
else if(this.scale=='F'||this.scale=='f' && t.scale=='c'||t.scale=='C')
{
temp=t.getFahrenheit();
if(this.degrees>=temp)
return true;
else
return false;
}
else
{
if(this.degrees>=t.degrees)
return true;
else
return false;
}
}
  
}

//Main.java

public class Main{
public static void main(String[] args)
{
Temperature t1=new Temperature(34.5,'c');
Temperature t2=new Temperature(94.5,'f');
if(t1.equals(t2))
System.out.println("t1 temperature equals t2");
else if(t1.lessThan(t2))
System.out.println("t1 temperature less than or equals t2");
else if(t1.greaterThan(t2))
System.out.println("t1 temperature is greater than or equal to t2");
//Now t1 and t2 objects are assingned with same values
t2.setDegrees(34.5);
t2.setScale('c');
if(t1.equals(t2))
System.out.println("t1 temperature equals t2");
  
}
}