The QUAD CLASS Solution

You are to implement a Quad class, such that you have both a ‘header file’ and an ‘implementation file ’ (see Chapter 11). The header file, Quad.h, provides class declaration and identifies public and private class members. The implementation file provides definitions for all member and friend functions.




A Quad object represents a Quadratic expression of degree 2, that is: ax2 + bx + c

For this assignment, the coefficients a, b and c are restricted to integers.




Public functions:

Quad()

Effect: create a Quadratic with a,b and c set to 0




Quad(int value)

Effect: creates a Quadratic with a=0, b=0, c = value




Quad(int a, int b, int c)

Effect: creates a Quadratic with the specified parameter values as coefficients




int eval(int value) const

Effect: evaluates the Quadratic for x = value

Postcondition: the Quad is unchanged

Returns: the computed result

For example, if the Quad equation was: 2x2 + 2x + 1

And method eval was called with value = 2, eval would return 14 ( 2*22 + 2*2 + 1)




int& operator[](int index)

Effect: set/access method for the coefficient of xindex

Returns: the coefficient of xindex




const Quad Quad::operator+(const Quad& qu) const // member function

Effect: overloads the + operator for Quad objects

Postcondition: this object and qu are unchanged

Returns: a new Quad object which is termwise sum of this object and qu




bool Quad::operator== (const Quad& q) const //member function

Effect: Compare this Quad to another object p to see if they are equal

Postcondition: this Quad object is unchanged

Returns:

A return value of true indicates that p refers to a Quad object

the same value as this Quad object. False is returned otherwise.




const Quad multiple(int value) const //member function

Effect: new Quad object is created in which each coefficient is a multiple of this object

Postcondition: this object is not changed

Returns: new object where each coefficient is ‘value times’ the coefficient of this object

(ie. this object a=2, b=4, c=3, value=6; new object a = 12, b =24, c = 18)

const Quad operator-() const // unary minus member function

Effect: new Quad object created identical to this one except coefficients are negated

Postcondition: this Quad object is unchanged

Returns: the new object




const Quad operator++() // autopreincrement member function

Effect: new Quad object created identical to this one after data is incremented

Postcondition: this Quad object coeffiecient are incremented by one

Returns: the new object




const Quad operator++(int) // autopreincrement member function

Effect: new Quad object created identical to this one before data is incremented

Postcondition: this Quad object coeffiecient are incremented by one

Returns: the new object

 

friend ostream& operator<<(ostream& out, const Quad& obj) //friend function

Effect: outputs a string representation of this Quad

Postcondition: this Quad object is unchanged

Returns: a string of the form: a x2 + b x + c

where a, b and c are the actual coeffients of the Quad object

 

Quad operator-(const Quad& qu1, const Quad& qu2) //non- friend, non-member function

Effect: overloads the binary - operator for Quad objects

Postcondition: qu1 and qu2 are unchanged

Returns: a new Quad object which is termwise difference of this qu1 and qu2




Application




Contains a function void coefIn(int& value) which prompts for and reads an integer into a string object. This function verifies that all characters in the string are digits, and converts the digits to its integer representation. The function continues to reprompt the user until a valid string is provided. The integer is returned via the parameter list.




You are to write an application (main program) which:

asks the user for coefficients a,b and c (use function coefIn(int& value))
creates a Quad object, and outputs it to the screen
performs a variety of operations on this Quad object (and/or others
created from it) such that all the correct operation of all is demonstrated.

Be sure to provide output which clearly provides the result of each

function call so that results can be verified.




test your functions in different scenerios – for example, statements such as
q4 = (q1 - 2) + (q3 + q2);

cout << "q4 is " << -q4 << endl;

q5 = -(q1 + q2 + 2 - q3);

cout << q5 << endl;




where q1,q2,q3,q4 and q5 are Quad object, should work correctly.




Submit files Quad.h, Quad.cpp, and your application.cpp file. Be sure that your name is included in each file and that all code is readable. Be sure to test your class thoroughly, as I will test it with applications other than your own.