本文学习自狄泰软件学院 唐佐林老师的 C语言进阶课程，图片全部来源于课程PPT，仅用于个人学习记录

*号

实验-指针的大小

#include <stdio.h>

int main()
{
    int i = 0;
    int* pI;
    char* pC;
    float* pF;

    pI = &i;

    *pI = 10;

    printf("%p, %p, %d\n", pI, &i, i);
    printf("%d, %d, %p\n", sizeof(int*), sizeof(pI), &pI);
    printf("%d, %d, %p\n", sizeof(char*), sizeof(pC), &pC);
    printf("%d, %d, %p\n", sizeof(float*), sizeof(pF), &pF);

    return 0;
}
/*output:
0060FEFC, 0060FEFC, 10
4, 4, 0060FEF8
4, 4, 0060FEF4
4, 4, 0060FEF0
*/

实验-传址交换数值

#include <stdio.h>

int swap(int* a, int* b)
{
    int c = *a;

    *a = *b;

    *b = c;
}

int main()
{
    int aa = 1;
    int bb = 2;

    printf("aa = %d, bb = %d\n", aa, bb);

    swap(&aa, &bb);

    printf("aa = %d, bb = %d\n", aa, bb);

    return 0;
}
/*output:
aa = 1, bb = 2
aa = 2, bb = 1
*/

实验-const与指针

#include <stdio.h>

int main()
{
    int i = 0;

    const int* p1 = &i;
    int const* p2 = &i;
    int* const p3 = &i;
    const int* const p4 = &i;

    //*p1 = 1;    // compile error
    p1 = NULL;  // ok

    //*p2 = 2;    // compile error
    p2 = NULL;  // ok

    *p3 = 3;    // ok
//    p3 = NULL;  // compile error

    //*p4 = 4;    // compile error
   // p4 = NULL;  // compile error

    return 0;
}

小结

指针是C语言中-种特别的变量

指针所保存的值是内存的地址

可以通过指针修改内存中的任意地址内容