数组做函数参数的退回问题　退回为一个指针,
1 正确做法：把数组的内存首地址和数组的有效长度传给被调用函数
2 //实参的a 和 形参的a 的数据类型本质不一样形参中的数组 ,编译器会把它当成指针处理 这是C语言的特色排序 本质也剖析
3 形参写在函数上,和写在函数内是一样的,只不过是具有对外的属性而已.(The return problem of the array as a function parameter is returned to a pointer,
1 correct method: pass the first address of the memory and the effective length of the array to the called function
2 / / a array data type of the a parameter and the essence of the argument is not the same as the parameter, the compiler will use it as a pointer processing this is the essence of the C language features analysis sorting
The 3 parameter is written in a function that is the same as written in a function, but it is only a foreign attribute.)