1. ADT Specification Example
TYPE
ComplexNumber
DOMAIN
Each complex number can represented by real and imaginary part.
OPERATIONS
Set the real part
set the imaginary part
get the real part
get the imaginary part
plus another complex number
minus another complex number
multiply another complex number
divide another complex number
compare with another complex number

2. Representations of ComplexNumber
2 double variables
2 float variables
actual choice of representation depends on actual application (possible values of complex number )

3. class Complex Specification
// SPECIFICATION FILE
class Complex // declares a class data type
{ // does not allocate memory
public : // public function members
void setReal ( double r ) ;
void setImg( double im);
double getReal();
double getImg();
Complex plus( Complex c);
Complex minus(Complex c);
Complex multiply(Complex c);
Complex divide( Complex c);
void print() const ;
bool Equal ( Complex c) const ;
private : // private data members
double real ;
double img ;
} ; 3

4. Use of C++ data Type class
software that uses the class is called a client
variables of the class type are called class objects or class instances
client code uses public member functions to handle its class objects

5. Client Code Using Complex
#include “comlex.h” // includes specification of the class
int main ( ) {
Complex num1, num2;
Complex sum;
double real, img;
cout<<“Enter the real and imaginary parts for the first numer\n”;
cin>>ral >> img;
num1.setReal(real);
num1.setImg(img);
cout<<“Enter the real and imaginary parts for the second number\n”;
cin>>real>>img;
num2.setreal(real);
num2.setImg(img);
sum = num1.plus(num2);
cout<< “the num1 + num2 =“<< sum.print()<,endl;
return 0; } 5

6. Implementation of plus function
Complex Complex::plus(Complex c) {
Complex sum;
sum.real = real + c.real;
sum.img = img + c.img;
return sum; }
// you complete implementations for minus, multiply and divide

7. Implementation of print function
Void Complex::print() const {
cout<<“ (“<<real <<“, “<<img<<“)”’ }

8. Implementation of set functions
void Complex::setReal(double r) {
real = r; }
// you write the implementation of
// setImg( double i)

9. Implementation of Compare
bool Complex::Equal(Complex c) {
if ( real == c.real && img == c.img)
return true;
else return false; }

10. Specification of Complex Class Constructors
class Complex // Complex.h {
public :
// function members
Complex( double real, double img ) ; // constructor
Complex ( ) ; // default constructor
private : // 2 data members
double real ;
double img ;
} ; 10

11. Implementation of Complex Default Constructor
Complex :: Complex ( ) {
real = 0 ;
img = 0 ; } 11

12. Implementation of Another Complex Class Constructor
Complex :: Complex ( /* in */ double r,
/* in */ double i) {
real = r ;
img = i ; } 12