.Net中的數字類型四則運算的有趣問題

看看下面的代碼:
     sbyte sba, sbb,sbv;
            sba = 1;
            sbb = 2;
            sbv = sba + sbb;

            byte ba, bb, bv;
            ba = 1;
            bb = 2;
            bv = ba + bb;

            short sa, sb, sv;
            sa = 1;
            sb = 2;
            sv = sa + sb;

            ushort usa, usb, usv;
            usa = 1;
            usb = 2;
            usv = usa + usb;

            MessageBox.Show(string.Format("{0},{1},{2},{3}", sbv, bv, sv, usv));
你覺得這段代碼能否正確執行?結果會怎樣?

用VS2005打開項目測試一下你就會發現,這段代碼會出現編譯錯誤.
正確的代碼應該如下:           
            sbyte sba, sbb,sbv;
            sba = 1;
            sbb = 2;
            sbv = (sbyte)(sba + sbb);

            byte ba, bb,