JAVA

Write a program that uses the class Calculator in Listing 9.12 to create a more powerful calculator. This calculator will allow you to save one result in memory and call the result back. The commands the calculator takes are

e for end

c for clear; sets result to zero

m for save in memory; sets memory equal to result

r for recall memory; displays the value of memory but does not change result

You should define a derived class of the class Calculator that has one more instance variable for the memory, a new main method that runs the improved calculator, a redefinition of the method handleUnknownOpException, and anything else new or redefined that you need. A sample interaction with the user is shown next. Your program need not produce identical output, but it should be similar and just as clear or even clearer.

Calculator on: result = 0.0 + 4 result + 4.0 = 4.0 updated result = 4.0 / 2 result / 2.0 = 2.0 updated result = 2.0 m result saved in memory c result = 0.0 + 99 result + 99.0 = 99.0 updated result = 99.0 / 3 result / 3.0 = 33.0 updated result = 33.0 r recalled memory value = 2.0 result = 33.0 + 2 result + 2.0 = 35.0 updated result = 35.0 e End of program