.NET (Core and Framework)

public class AClass
{
    public AClass()
    {
       //constructor 1
    }

    public AClass(int arg1) : this()
    {
        //constructor 2
    }

    public AClass(int arg1, string arg2) : this(arg1)
    {
        //constructor 3
    }

}

class Foo {
    public Foo() : this("sensibledefaultvalue") {}
    public Foo(string arg1) : this(arg1, "otherdefaultvalue") {}
    public Foo(string arg1, string arg2) { 
        // do the real work, knowing both args will be defaulted in
    }
}