如果把两个函数的位置对换一下,即先写main函数,后写max函数,这时在编译main函数遇到max时,编译系统无法知道max代表什么含义,因而无法编译,按出错处理｡ -If the position of the two functions change, the first to write the main function, written after the max function, At this time, the compiled main function e