Java constructor

Question

Hi!
My program is ok but I have problem with my second constructor without
parameter. How do I write this constructor? toString method is ok and can reache first constructor but not the second constructor. and how do I call it in my main method.
class ComplexNumber
     private double re;
     private double imag;
    public ComplexNumber ( double  real, double imaginary )
          re=real;
          imag=imaginary;
     public ComplexNumber()
       re=  ;
       imag= ;
    public double getReal(  )
          return re;
    public double getImaginary( )
           return imag;
    public  ComplexNumber  add ( ComplexNumber x )
          ComplexNumber  newComplex = new ComplexNumber();
          ComplexNumber  MyComplex =  this;        
          newComplex.re = MyComplex.re+x.re;
          newComplex.imag = MyComplex.imag+x.imag;
          return  newComplex;      
    public static final ComplexNumber  add ( ComplexNumber x, ComplexNumber y )
          ComplexNumber  newComplex = new ComplexNumber();
          newComplex.re = x.re+y.re;
          newComplex.imag = x.imag+y.imag;
          return  newComplex;
    public static final ComplexNumber  sub ( ComplexNumber x, ComplexNumber y )
       ComplexNumber  newComplex = new ComplexNumber();
          newComplex.re = x.re-y.re;
          newComplex.imag = x.imag-y.imag;
          return  newComplex;
    public static final ComplexNumber  mult  ( ComplexNumber x, ComplexNumber y )
         ComplexNumber  newComplex = new ComplexNumber();
         newComplex.re  = x.re * y.re - x.imag* y.imag;
         newComplex.imag= x.re * y.imag + x.imag * y.re;
         return newComplex;
  /*      public static final ComplexNumber  div ( ComplexNumber x, ComplexNumber y)
    public String toString()
          if(imag< 0)
              return re+" - " +(-imag)+"  i ";
          if(imag== 0)
              return re+ " ";
          if(re== 0)
              return imag+"  i "; 
          return re+" + " +imag+"  i ";
   public static void main(String[]args     )
          ComplexNumber com1 = new ComplexNumber(5,-6);
          ComplexNumber com2 = new ComplexNumber(-3,4);
          ComplexNumber myCom = new ComplexNumber();
        System.out.println("         COMPLEX NUMBERS              "); 
    System.out.println("--------------------------------------");
        System.out.println(" Complex number   1:    "+ com1);
        System.out.println(" Complex number   2:   "+ com2);
        System.out.println("======================================");
        System.out.println();
        System.out.println(" Complex nbr1 + nbr2:   "+ add(com1,com2));
        System.out.println();
        System.out.println(" Complex nbr1 - nbr2:   "+ sub(com1, com2));
        System.out.println();
        System.out.println(" Complex nbr1 * nbr2:   "+ mult(com1, com2));
        System.out.println();
    //System.out.println(" Complex nbr1 / nbr2:   "+ divide(com1, com2));
    System.out.println();
    System.out.println("======================================");
        System.out.println(" Complex nbr1 + nbr2:   "+ com1.add(com2));
        System.out.println(myCom.getReal());
        System.out.println(myCom.getImaginary());
 

Answer 1

Now my constructor is ok but How can I count different
complex nbrs with this constructor. I mean in main metod.
     public ComplexNumber()
      re=4;
      imag=5;
public  ComplexNumber  add ( )
          ComplexNumber  newComplex1 = new ComplexNumber();
          ComplexNumber  newComplex2 = new ComplexNumber();
          ComplexNumber  newComplex3 = new ComplexNumber();
          newComplex1.re = newComplex2.getReal()+newComplex3.getReal();
          newComplex1.imag= newComplex2.getImaginary( )+newComplex3.getImaginary( );
          return  newComplex1;      
// main method
System.out.println(" Complex nbr1 + nbr2:   "+myCom);