用三种方法遍历数组

  //声明一个数组            int[] num =new int[3]{4,6,2};            int a = num.Length;//得到数组的长度            for (int i = 0; i < a; i++)            {                Console.WriteLine(num[i]);            }            int j=0;            while(j<a){                Console.WriteLine(num[j]);                j++;            }            foreach (int temp in num)            {                Console.WriteLine(temp);            }