学步园

看如下代码：

DateTime startTime;
            DateTime endTime;
            long i;
           
            //i = i + 1
            i = 0;
            startTime = DateTime.Now;
            while (i < 10000000000)
            {
                i = i + 1;
            }
            endTime = DateTime.Now;
            Console.WriteLine("i = i + 1");
            Console.WriteLine((endTime.Minute - startTime.Minute) + "分" + (endTime.Second - startTime.Second) + "秒" + (endTime.Millisecond - startTime.Millisecond) + "毫秒");

            //i++
            i = 0;
            startTime = DateTime.Now;
            while (i < 10000000000)
            {
                i++;
            }
            endTime = DateTime.Now;
            Console.WriteLine("i++");
            Console.WriteLine((endTime.Minute - startTime.Minute) + "分" + (endTime.Second - startTime.Second) + "秒" + (endTime.Millisecond - startTime.Millisecond) + "毫秒");

            //i += 1
            i = 0;
            startTime = DateTime.Now;
            while (i < 10000000000)
            {
                i += 1;
            }
            endTime = DateTime.Now;
            Console.WriteLine("i += 1");
            Console.WriteLine((endTime.Minute - startTime.Minute) + "分" + (endTime.Second - startTime.Second) + "秒" + (endTime.Millisecond - startTime.Millisecond) + "毫秒");

结果如下：

i = i + 1
0分36秒130毫秒
i++
1分-24秒239毫秒    //等价36秒239毫秒
i += 1
1分-24秒130毫秒   //等价36秒130毫秒
请按任意键继续. . .

结论：C#中、i = 1+ 1;i++;i += 1之性能可以忽略