checked、is、as、sizeof、typeof運(yùn)算符、空合并運(yùn)算符

 //--------------------------------checked防止溢出
            byte b = 255;
            checked
            {
                b++;
            }
            Console.WriteLine(b.ToString());//byte類型只包含0~255，加上checked所以會(huì)拋出異常

            //is運(yùn)算符，檢查對(duì)象是否與特定的類型兼容
            int i = 0;
            Console.WriteLine(i is object);//True

            //--------------------------------as運(yùn)算符，顯示轉(zhuǎn)換特定的類型
            object o = "123";
            string s = o as string;
            Console.WriteLine(s);

            //--------------------------------sizeof運(yùn)算符，可以確定棧中值類型的長(zhǎng)度
            Console.WriteLine(sizeof(int));//輸出4

            //--------------------------------typeof運(yùn)算符,返回一個(gè)特定類型的System.Type對(duì)象
            Console.WriteLine(typeof(string));//輸出System.String
           
            Console.ReadKey();

            //--------------------------------可空運(yùn)算符與空合并運(yùn)算符

            int? i = null;//int?可空運(yùn)算符
            int? a = i ?? 10;//空合并運(yùn)算符 （如果??前面是空則等于第二個(gè)值）
            Console.WriteLine(a);//輸出10
            Console.ReadKey();