标签：pre 返回值 res print sum 通过 stat code http
1.除了数组外，其他都有副本机制（包括结构体数组）
2.结构体作为参数具有副本机制，结构体返回值也有副本机制 。
3.函数的参数和返回值都有他的副本机制。
#include<stdio.h> int a=10,b=20; static int sum(int aa,int bb){ printf("the aa is 0x%p,%d",&aa,aa); printf("\nthe bb is 0x%p,%d",&bb,bb); aa=100; return a+b; } int main(){ sum(a,b); printf("\nthe a is 0x%p,%d",&a,a); printf("\nthe b is 0x%p,%d",&b,b); }
形参aa和bb是对a和b地址的拷贝。
#include<stdio.h> int array[2]={10,20}; static int arr(int arra[2]){ printf("\nthe array is 0x%p,%d",arra,arra[0]); arra[0]=123; return arra[0]+arra[1]; } int main(){ arr(array); printf("\nthe array is 0x%p,%d",array,array[0]); return 0; }
形参arra传入的是array的实际地址。
#include<stdio.h> typedef struct{ int ar[10]; int a; }Struct; Struct my; static void fuzhif(Struct mystruct){ mystruct.a=10; mystruct.ar[0]=0; printf("\nthe mystruct address is:0x%p,ar address is:0x%p,%d,%d",&mystruct,mystruct.ar,mystruct.a,mystruct.ar[0]); } int main(){ my.a=100; my.ar[0]=100; printf("\nthe my address is:0x%p,ar address is:0x%p,%d,%d",&my,my.ar,my.a,my.ar[0]); fuzhif(my); printf("\nthe my address is:0x%p,ar address is:0x%p,%d,%d",&my,my.ar,my.a,my.ar[0]); return 0; }
形参mystruct传入的是结构体my的地址的拷贝。
#include<stdio.h> typedef struct{ int ar[10]; int a; }Struct; Struct my; static void fuzhit(Struct *mystruct){ mystruct->a=10; mystruct->ar[0]=0; printf("\nthe mystruct address is 0x%p,ar address is:0x%p,%d,%d",mystruct,mystruct->ar,mystruct->a,mystruct->ar[0]); } int main(){ my.a=100; my.ar[0]=100; printf("\nthe my address is:0x%p,ar address is:0x%p,%d,%d",&my,my.ar,my.a,my.ar[0]); fuzhit(&my); printf("\nthe my address is:0x%p,ar address is:0x%p,%d,%d",&my,my.ar,my.a,my.ar[0]); return 0; }
如果形参为结构体变量，那么可以通过结构体指针修改某一结构体变量的值。
标签：pre 返回值 res print sum 通过 stat code http
原文地址：https://www.cnblogs.com/ligei/p/11363626.html
