1 #include <bits/stdc++.h> 2 using namespace std; 3 class complexed 4 { 5 public: 6     complexed(); 7     complexed(double real); 8     complexed(double real,double imag); 9     void display();10     void set(double r,double i);11 private:12     double real,imag;13 };14 complexed::complexed()15 {16     set(0.0,0.0);17     cout<<"default constructor.\n";18 }19 complexed::complexed(double real)20 {21     set(real,0.0);22     cout<<"construct called.\n";23 }24 complexed::complexed(double real,double imag)25 {26     set(real,imag);27     cout<<"constructor :real="<<real<<",imag="<<imag<<endl;28 }29 void complexed::display()30 {31     if(imag<0)32         cout<<real<<imag<<‘i‘<<endl;33     else34         cout<<real<<‘+‘<<imag<<‘i‘<<endl;35 }36 void complexed::set(double r,double i)37 {38     real=r;39     imag=i;40 }41 int main()42 {43     complexed c1;44     complexed c2(6.8);45     complexed c3(5.6,7.9);46     c1.display();47     c2.display();48     c3.display();49     c1=complexed(1.2,3.4);50     c2=5;51     c3=complexed();52     c1.display();53     c2.display();54     c3.display();55 }