I have 2 classes: Temperature and the driver class.

Can someone tell me why the following scenarios (in testing 2
temperatures) are notworking right?

Scenarios (1)  and (2): If I compare the two temperature in same unit,
i.e both in C and both in F, with one number bigger than the other, I
get error.

(3): Using the same float value, I create a second object in unit C and
the third object in F.

(4): Using the same float value, I create a second object in unit C and
the third object in F.

In both (3) and (4), the program displays - I have a display method of
the temperature netered - the 3rd object with unit of 2nd object but
when comparing using comparison =, >=, <=, scenarios (3) is okay but
scenarios (4) is not.

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Here is the code for the driver:
**********************************************************************************************

                                            HW_413_7_driver

************************************************************************************************/

import java.util.Scanner;
import java.util.*;
import java.io.*;

public class HW_413_7_driver
{

    public static void main( String[] Args)
    {

   System.out.println();
    System.out.println();

     Scanner keyboard =  new Scanner(System.in);
   System.out.println("Enter a float value with 2 decimal position for
a temperature.");
   float temp = keyboard.nextFloat();
   System.out.println("Enter one character for degree scale (C or
F).");
   String strScale = keyboard.next();
   char scale = strScale.charAt(0);

   HW_413_7_Temperature t2 = new HW_413_7_Temperature(temp,scale);

    System.out.print("Second Temperature is ");

   t2.display(); System.out.println(); System.out.println();

  Scanner keyboard3 =  new Scanner(System.in);
   System.out.println("Enter a float value with 2 decimal position for
a temperature.");
   float temp3 = keyboard3.nextFloat();
   System.out.println("Enter one character for degree scale (C or
F).");
   String strScale3 = keyboard.next();
   char scale3 = strScale.charAt(0);

   HW_413_7_Temperature t3 = new HW_413_7_Temperature(temp3,scale3);

    System.out.print("Third Temperature is ");

   t3.display(); System.out.println(); System.out.println();

  if ( (t2.equals(t3) )== true)
   {
     t2.display(); System.out.print(" is equal to "); t3.display();
   }
   else
   {
     t2.display(); System.out.print(" is NOT equal to ");
t3.display();
   }

  System.out.println();

  if ( ( t2.isGreater(t3) )== true)
  {
   t2.display(); System.out.print(" is greater than "); t3.display();
  }

  else
    {
        t2.display(); System.out.print(" is NOT greater than ");
t3.display();
    }

  System.out.println();

  if ( (t2.isLess(t3) )  == true)
   {
    t2.display(); System.out.print(" is less than "); t3.display();
    }
  else
  {
    t2.display(); System.out.print(" is NOT less than ");t3.display();
  }

     System.out.println();

} // end main

}

------------------------------------------------------------------------------------------------------------------------

Here is for Temperature class:
/***********************************************************************************************

                                            HW_413_7_Temperature

Pg 413.7: Write a temperature class that has 2 parameters: a
temperature value (floating point
          number) and a character for the scale ('C' or 'F');
     - 4 constructors
     - 2 accessor methods (get methods) where conversion is done as
required
     - 3 mutator methods (set methods)
     - three comparison mehtods: is equal to, is greater than, is less
than

************************************************************************************************/

import java.util.Scanner; // for Scanner class
import java.text.NumberFormat;
import java.text.DecimalFormat;

public class HW_413_7_Temperature
{
 private float temperature;
 private char charScale=' ';

  // default constructor
  public HW_413_7_Temperature()
  {
    temperature = 0;
    charScale = 'C';
  }

  // constructor with a parameter
  public HW_413_7_Temperature(float newTemperature)
  {
      setTemparature(newTemperature);
      charScale = 'C';
  }

  // constructor with a parameter
  public HW_413_7_Temperature(char newCharScale)
  {
      temperature = 0;
    setCharScale(newCharScale);
  }

  // constructor with two parameters
  public HW_413_7_Temperature(float newTemperature, char newCharScale)
  {
      //setTemparature(newTemperature);
    //setCharScale(newCharScale);

    setTemperatureNCharScale(newTemperature, newCharScale);
  }

    public String getFarenheitTemperature()
  {      // use given formula: degreesF= (9 (degreesC/5) + 32;

    // here, this keyword contains both float and char; so how to retrive
just float
    float degreesF = (9 * ((this.temperature)/5))+ 32;
    NumberFormat n = NumberFormat.getInstance();
    n.setMaximumFractionDigits(2);
    return(n.format(degreesF)); // return as String as required
    }

// accessor method ROUND TO THE NEAREST TENTH OF A DEGREE
  public String getCelsiusTemperature()
  {
    // use given formula: degreesC = 5*(degreesF - 32)/9;

    // here, this keyword contains both float and char; so how to retrive
just float
    float degreesC = 5*((this.temperature) - 32)/9;
    DecimalFormat df = new DecimalFormat("###.00");
    return(df.format(degreesC)); // return as String as required
  }
  // mutator method with 1 parameter
  public void setTemparature(float newTemperature)
  {
     temperature = newTemperature;
  }

  // mutator method with 1 parameter
  public void setCharScale(char newCharScale)
  {
    charScale = newCharScale;
  }

  // mutator method with 2 parameters
  public void setTemperatureNCharScale(float newTemperature, char
newCharScale)
  {
     temperature = newTemperature;
    charScale = newCharScale;
  }

// call on driver as t1.equals(t2)
public boolean equals(HW_413_7_Temperature Temperature2)
{
    float temp1;
    char scale1 = this.charScale;

    if (scale1=='C')
        temp1 = this.temperature;
    else
          temp1 = Float.parseFloat(this.getCelsiusTemperature() );

   float temp2 = Float.parseFloat(Temperature2.getCelsiusTemperature()
);
        // need to parse to float in order to compare

    return (temp1==temp2);
}

// call on driver as t1.isGreater(t2)
public boolean isGreater(HW_413_7_Temperature Temperature2)
{
    //float temp1 = this.temperature;
    //float temp2 = Float.parseFloat(Temperature2.getCelsiusTemperature()
);
    // need to parse back to float in order to compare

    float temp1;
    char scale1 = this.charScale;

    if (scale1=='C')
        temp1 = this.temperature;
    else
          temp1 = Float.parseFloat(this.getCelsiusTemperature() );

   float temp2 = Float.parseFloat(Temperature2.getCelsiusTemperature()
);
        // need to parse to float in order to compare

    return (temp1>=temp2);
}

// call on driver as t1.isLess(t2)
public boolean isLess(HW_413_7_Temperature Temperature2)
{
    //float temp1 = this.temperature;
    //float temp2 = Float.parseFloat(Temperature2.getCelsiusTemperature()
);
    // need to parse to float in order to compare
    float temp1;
    char scale1 = this.charScale;

    if (scale1=='C')
        temp1 = this.temperature;
    else
          temp1 = Float.parseFloat(this.getCelsiusTemperature() );

   float temp2 = Float.parseFloat(Temperature2.getCelsiusTemperature()
);
        // need to parse to float in order to compare

    return (temp1<=temp2);

}
// to display temperature entered as it is
public void display()
{
 System.out.print(this.temperature);
 System.out.print(" in ");
 System.out.print(this.charScale);
}

} // end class