[問題] 有那位大大能幫小弟解決這個問題?

[smallanghome (良仔)]

我執行到o5後就印不出來了，誰能幫我解決這個問題...感激不盡！
    class Program
    {
        static void Main()
        {
            A o1 = new A();
            A o2 = new A(3);
            A o3 = new A(10, 2.3);
            A o4 = new A("HELLO");
            A o5 = new A(o4);//不太懂這個意思
            A o6 = o5;
        }
    }
    class A
    {
        public A()
        {
            Console.WriteLine("A()");
        }
        public A(int a)
        {
            Console.WriteLine("A({0})",a);
        }
        public A(int b,double c)
        {
            Console.WriteLine("A({0},{1})", b, c);
        }
        public A(string d)
        {
            Console.WriteLine("A({0})", d);
        }
        public A(//到這會出錯，好像說有重複。)
        {
            Console.WriteLine("A({0})",e);
        }
        public A()
        {
            Console.WriteLine("A({0})",f);
        }

    }

--
※ 發信站: 批踢踢實業坊(ptt.cc) 
◆ From: 59.113.9.121
推 Fadis:public A()  共定義了3次??