指针（pointer）的使用

Posted 2020-11-16 hehesunshine

1、变量的指针和指针的变量

变量的指针：变量的存储地址，

指针变量：存储指针的变量

2、指针变量的基本符号

&：取地址符号

*：间接取址符号

NULL||0：初始化

**：多级指针

*p[]：指针数组

3、程序实例（自己 尝试写类函数，一直不懂啥时候才定义变量位为private

 1 //*m:定义指针变量  &m：取m的地址 *&m：间接访问 m的内容
 2 //&和 *互为逆运算
 3 
 4 #include <iostream>
 5 #include<stdlib.h>
 6 using namespace std;
 7 /*void main(){
 8     int *x, *y;
 9     int m, n;
10     cout << "请输入m和n" << endl;
11     cin >> m >> n ;
12     x = &m;
13     y = &n;
14     cout << *x << " " << *y << endl;
15     int *temp;
16     temp = x;
17     x = y;
18     y = temp;
19     cout << *x << " " << *y << endl;
20 
21 }*/
22 class pointer{
23 public:
24     void _cinvlauemn();
25     void _cinvaluea();
26     void _swappointer();
27     void _pointerarray();
28 private:
29     int m, n;
30     int a[5];
31 };//一定要记得输入分号
32 void pointer::_cinvlauemn(){
33     cout << "请输入m和n" << endl;
34     cin >> m >> n;
35 }
36 void pointer::_cinvaluea(){
37     cout << "请输入数组值： " << endl;
38     for (int i = 0; i < sizeof(a) / sizeof(int); i++){
39         cin >> a[i];
40     }
41 }
42 void pointer::_swappointer(){
43     int *x=NULL, *y=0;//初始化
44     x = &m;
45     y = &n;
46     cout << *x << " " << *y << endl;
47     int *temp;
48     temp = x;
49     x = y;
50     y = temp;
51     cout << *x << " " << *y << endl;
52 }
53 void pointer::_pointerarray(){
54     int *p[5];
55     for (int i = 0; i < 5; i++){
56         p[i] = &a[i];
57     }
58     int **pp;
59     pp = p;//把指针数组p的首地址给pp
60     for (int i = 0; i < 5; i++){
61         cout << **pp << " ";
62         pp++;
63     }
64 }
65 void main(){
66     pointer function;
67     function._cinvlauemn();
68     function._cinvaluea();
69     function._swappointer();
70     function._pointerarray();
71 }

4、运行结果