c语言 参数传值和传地址

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static void TestCharP(char **p) {     char *q = "ssssss";     *p=q; }   static void TestCharP1(char *p) {     char *q = "ssssss";     p=q; }   static void TestInt(int *a) {     *a = 5; }   static void TestInt1(int a) {     a = 5; }   static void TestBuf(char buf[]) {     buf[0] = 'a'; }     //传值和传地址的区别 int main() {     int a = 0;     int a1 = 0;     char *p=NULL;     char buf[5] = {0};     char *p1 = NULL;       TestInt(&a);     printf("%d\n",a);       TestInt1(a1);     printf("%d\n",a1);       TestCharP(&p);     printf("%s\n",p);       TestCharP1(p1);     printf("%s\n",p1);       TestBuf(buf);     printf("%s\n",buf);       return 0; }

输出：

 

2.查看地址转换

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static void TestCharP(char *p) {     //p指向地址：0x00045860     char *q = "ssssss";     //q指向地址：0x00045858     p=q;     //p指向地址：0x00045858 }     //传值和传地址的区别 int main() {     char *p="aaa";     //p指向地址：0x00045860     TestCharP(p);     //p指向地址：0x00045860     printf("%s\n",p);       return 0; }

查看 p指向地址没有改变

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static void TestCharP(char **p) {     //*p指向地址：0x0014f888     char *q = "ssssss";     //q指向地址：0x01185858     *p=q;     //*p指向地址：0x01185858 }     //传值和传地址的区别 int main() {     char *p="aaa";     //p指向地址：0x01185860     TestCharP(&p);     //p指向地址：0x00045858     printf("%s\n",p);       return 0; }

　　查看 p指向地址改变