Constructors with default values of parameters

Does java support constructor with default valued parameters e.g. public Shape(int v=1,int e =2){vertices =v; edges = e; }

Yes,you can give defualt value to constructor

No, Java doesn't support default values for parameters. You can overload constructors instead:

public Shape(int v,int e) {vertices =v; edges = e; }
public Shape() { this(1, 2); }

No it doesn't. Java doesn't support default arguments in any function.

What you can do though is define public Shape(int v, int e) and also a default constructor

public Shape()
{
    this(1, 2);
}