问题集锦

1. try {}里有一个return语句，那么紧跟在这个try后的finally {}里的code会 不会被执行，什么时候被执行，在return前还是后?

答：会执行，在return前执行。

 

2. short s1 = 1; s1 = s1 + 1;有什么错? short s1 = 1; s1 += 1;有什么错 ?

答：short s1 = 1; s1 = s1 + 1;有错，s1是short型，s1+1是int型,不能显式

转化为short型。可修改为s1 =(short)(s1 + 1) 。short s1 = 1; s1 += 1正

确。

long型没关系

 

 3. 获取分数最低的记录（可能有多条） SELECT TOP 1  with ties *
  FROM [test].[dbo].[users] order by score asc

注：使用with ties 必须 有order by

4. 虚函数

 

static void Main(string[] args)
        {       A a = new A(); C c = new C();  }

 

   public class A
    {public A(){ Console.WriteLine("DEBUG: A constructing"); this.GetYear();}

      public virtual void GetYear(){Console.WriteLine("A");}
    }

    public class B:A
    {public B():base(){Console.WriteLine("DEBUG: B constructing");this.GetYear();}

      public override void GetYear(){Console.WriteLine("B");}
    }

    public class C : B
    {public C(){Console.WriteLine("DEBUG : C constructing");this.GetYear();}

       public override void GetYear(){Console.WriteLine("C");}

}

 

DEBUG: A constructing

A

DEBUG: A constructing

C

DEBUG: B constructing

C

DEBUG: C constructing

C