Question

In this assignment, you will write a subclass of the MemoryCalc class from Sixth Assignment – Memory Calculator. This new calculator, called ScientificMemCalc, should be able to do everything that the MemoryCalc could do, plus raise the current value to a power and compute the natural logarithm of the current value. This is a fairly realistic assignment – often when you are working for a company, you will be asked to make minor extensions to existing code. You will need to override the displayMenu method to add the new options. Be sure to only add code to the ScientificMemCalc class if it is necessary – leverage the code from the base MemoryCalc class whenever possible. Use the power of inheritance to do this rather than cutting and pasting or otherwise duplicating the code. Finally, write a new class called ScientificCalcDriver that shows the functionality of your new class. This will be very similar to the CalcDriver class.

MEMORYCALC:

import java.util.Scanner;

public class MemoryCalc {

private double currentValue;

public double getCurrentValue() {

return currentValue;

}

public void setCurrentValue(double currentValue) {

this.currentValue = currentValue;

}

public int displayMenu() {

Scanner input = new Scanner(System.in);

int choice = -1;

while (choice < 1 || choice > 6) {

System.out.println();

System.out.println("Menu");

System.out.println("1. Add");

System.out.println("2. Subtract");

System.out.println("3. Multiply");

System.out.println("4. Divide");

System.out.println("5. Clear");

System.out.println("6. Quit");

System.out.println();

System.out.print("What would you like to do? ");

choice = input.nextInt();

if (choice < 1 || choice > 6) {

System.out.println(choice + " wasn't one of the options");

}

if (choice == 6) {

System.out.println("Goodbye!");

System.exit(0);

}

}

return choice;

}

public double getOperand(String prompt) {

Scanner input = new Scanner(System.in);

System.out.print(prompt);

return input.nextDouble();

}

public void add(double op2) {

currentValue += op2;

}

public void subtract(double op2) {

currentValue -= op2;

}

public void multiply(double op2) {

currentValue *= op2;

}

public void divide(double op2) {

if (op2 == 0) {

currentValue = Double.NaN;

} else {

currentValue /= op2;

}

}

public void clear() {

currentValue = 0;

}

}

_____________________________________

CalcDriver

public class CalcDriver {

public static void main(String[] args) {

MemoryCalc calc = new MemoryCalc();

while (true) {

System.out.println("The current value is " + calc.getCurrentValue());

int choice = calc.displayMenu();

double second = 0;

if (choice < 5) {

second = calc.getOperand("What is the second number? ");

}

if (choice == 1) {

calc.add(second);

} else if (choice == 2) {

calc.subtract(second);

} else if (choice == 3) {

calc.multiply(second);

} else if (choice == 4) {

calc.divide(second);

} else if (choice == 5) {

calc.clear();

}

}

}

}

The output should look somewhat the same except with these changes.

Menu 1. Add 2. Subtract 3. Multiply 4. Divide 5. Power 6. Logarithm 7. Clear 8. Quit What would you like to do? 4 What is the second number? 6 The current value is 5.0 Menu 1. Add 2. Subtract 3. Multiply 4. Divide 5. Power 6. Logarithm 7. Clear 8. Quit What would you like to do? 5 What is the second number? 2 The current value is 25.0 Menu 1. Add 2. Subtract 3. Multiply 4. Divide 5. Power 6. Logarithm 7. Clear 8. Quit What would you like to do? 6 The current value is 3.2188758248682006

Answer 1

Answer:

Main.java (ScientificCalcDriver.java):

public class Main
{
//main function
public static void main(String[] args)
{
//create the object for ScientificMemCalc class
ScientificMemCalc c = new ScientificMemCalc();
while (true)
{
//display the current value
System.out.println("The current value is " + c.getCurrentValue());
//read choice from user
int choice = c.displayMenu();
double operand2 = 0;
if (choice < 6)
{
//get oeprand2 from user
operand2 = c.getOperand("What is the second number? ");
}
if (choice == 1)
{
c.add(operand2);
}
else if (choice == 2)
{
c.subtract(operand2);
}
else if (choice == 3)
{
c.multiply(operand2);
}
else if (choice == 4)
{
c.divide(operand2);
}
else if(choice==5)
{
c.power(operand2);
}
else if(choice==6)
{
c.logarithm();
}
else if (choice == 7)
{
c.clear();
}
}
}
}

MemoryCalc.java:

import java.util.Scanner;
public class MemoryCalc
{
protected double currentValue;
public double getCurrentValue()
{
return currentValue;
}
public void setCurrentValue(double currentValue)
{
this.currentValue = currentValue;
}
public int displayMenu()
{
Scanner choose = new Scanner(System.in);
int choice = -1;
while (choice < 1 || choice > 6)
{
System.out.println();
System.out.println("Menu");
System.out.println("1. Add");
System.out.println("2. Subtract");
System.out.println("3. Multiply");
System.out.println("4. Divide");
System.out.println("5. Power");
System.out.println("6. Logarithm");
System.out.println("7. Clear");
System.out.println("8. Quit");
System.out.println();
System.out.print("What would you like to do? ");
choice = choose.nextInt();
if (choice < 1 || choice > 8)
{
System.out.println(choice + " wasn't one of the options");
}
if (choice == 8)
{
System.out.println("Goodbye!");
System.exit(0);
}
}
return choice;
}
//method for getOperand
public double getOperand(String prompt)
{
Scanner choose = new Scanner(System.in);
System.out.print(prompt);
return choose.nextDouble();
}
//method for add
public void add(double operand2)
{
currentValue += operand2;
}
//method for subtract
public void subtract(double operand2)
{
currentValue -= operand2;
}
//method for multiply
public void multiply(double operand2)
{
currentValue *= operand2;
}
//method for divide
public void divide(double operand2)
{
if (operand2 == 0)
{
currentValue = Double.NaN;
}
else
{
currentValue /= operand2;
}
}
//method for clear
public void clear()
{
currentValue = 0;
}
}

ScientificMemCalc.java:

import java.util.Scanner;
//class for ScientificMemCalc
public class ScientificMemCalc extends MemoryCalc
{
//method definition for power
public void power(double operand2)
{
this.currentValue=Math.pow(this.getCurrentValue(),operand2);
}
//method definition for logarithm
public void logarithm()
{
this.currentValue= Math.log(this.getCurrentValue());
}
//method for displayMenu
public int displayMenu()
{
return super.displayMenu();
}
}

Sample Output The current value is θ.0 Menu 1. Add 2. Subtract 3. Multiply 4. Divide 5. Power 6. Logarithm 7. Clear 8. Quit what would you like to do? 1 What is the second number? 30 The current value is 30.e Menu 1. Add 2. Subtract 3. Multiply 4. Divide 5. Power 6. Logarithm 7. Clear 8. Quit what would you like to do? 4 What is the second number? 6 The current value is 5.0

Menu 1. Add 2. Subtract 3. Multiply 4. Divide 5. Power 6. Logarithm 7. Clear 8. Quit what would you like to do? 5 What is the second number? 2 The current value is 25.0 Menu 1. Add 2. Subtract 3. Multiply 4. Divide 5. Power 6. Logarithm 7. Clear 8. Quit what would you like to do? 6 The current value is 3.2188758248682006 Menu 1. Add 2. Subtract 3. Multiply 4. Divide 5. Power 6. Logarithm 7. Clear 8. Quit what would you like to do? 8 Goodbye!