for循环的几种常见变形

            int result = 0;
            for (int i = 0; i <= 10; i++)
            ...{
                result = result + i;
            }

这个大家都看得懂,for(int =0;i<=10;i++)标准的for循环,来看下面一个:for (; i <= 10;)  这个什么意思?

 

            int result = 0;
            int i = 0;
            for (; i <= 10;)
            ...{
                result = result + i;
                i++;
            }

比较一下while循环

 

            int result = 0;
            int i = 0;
            while  ( i <= 10)
            ...{
                result = result + i;
                i++;
            }

 

好象上面的while循环和for循环差别不大.相互间可以轻易转换.

继续再把for精简一下,for (; ;)  这样还可以 

            int result = 0;
            int i = 0;
            for (;;) 
            ...{
                if (i <= 10)
                ...{
                    result = result + i;
                    i++;
                    continue;
                }
                else
                ...{
                    break;
                }
            }