指针

 

  1 #include<iostream>
  2 using namespace std;
  3 
  4 
  5 
  6 int main()
  7 {
  8     int i = 10;
  9     int *p;
 10     p = &i;
 11     int *p1;
 12     p1 = p;
 13 
 14     /*
 15     &i:003AFA30
 16     &p:003AFA24
 17     p:003AFA30
 18     *p:10
 19     p1:003AFA30
 20     &p1:003AFA18
 21     *p1:10
 22 
 23     => &i = p = p1
 24     => *p = *p1
 25     */
 26     cout << "&i:"<< &i << endl;
 27     cout << "&p:" << &p << endl;
 28     cout << "p:" << p << endl;
 29     cout << "*p:" << *p << endl;
 30     cout << "p1:"<< p1 << endl;
 31     cout << "&p1:" << &p1 << endl;
 32     cout << "*p1:" << *p1 << endl;
 33     cout << "--------------------------------" << endl;
 34 
 35 
 36     int **p2 = NULL;
 37     int *p3 = NULL;
 38     int *p4 = NULL;
 39     int j = 20;
 40     
 41     p3 = &j;
 42     p4 = p3;
 43     p2 = &p3;
 44     /*
 45     &j:0074FBF8
 46     p3:0074FBF8
 47     *p3:20
 48     &p3:0074FC10
 49     p4:0074FBF8
 50     &p4:0074FC04
 51     *p4:20
 52     p2:0074FC10
 53     &p2:0074FC1C
 54     *p2:0074FBF8
 55     **p2:20
 56 
 57     =>    &j = p3 = p4
 58     =>    p2 = &p3
 59     =>    *p2 = &j
 60     =>    **p2 = j
 61     */
 62     cout << "&j:" << &j << endl;
 63     cout << "p3:" << p3 << endl;
 64     cout << "*p3:" << *p3 << endl;
 65     cout << "&p3:" << &p3 << endl;
 66     cout << "p4:" << p4 << endl;
 67     cout << "&p4:" << &p4 << endl;
 68     cout << "*p4:" << *p4 << endl;
 69     cout << "p2:" << p2 << endl;
 70     cout << "&p2:" << &p2 << endl;
 71     cout << "*p2:" << *p2 << endl;
 72     cout << "**p2:" << **p2 << endl;
 73     cout << "--------------------------------" << endl;
 74 
 75     int ***k, **k1, *k2;
 76     int m = 30;
 77 
 78     k2 = &m;
 79     k1 = &k2;
 80     k = &k1;
 81     /*
 82     &m:009BFB68
 83     k2:009BFB68
 84     &k2:009BFB74
 85     *k2:30
 86     k1:009BFB74
 87     &k1:009BFB80
 88     *k1:009BFB68
 89     k:009BFB80
 90     &k:009BFB8C
 91     *k:009BFB74
 92     **k:009BFB68
 93     ***k:30
 94 
 95     =>    &m = k2 = *k1 = **k
 96     =>    &k2 = k1 = *k
 97     =>    &k1 = k
 98     =>    *k2 = ***k
 99     */
100     cout << "&m:"<<&m << endl;
101     cout << "k2:" << k2 << endl;
102     cout << "&k2:" << &k2 << endl;
103     cout << "*k2:" << *k2 << endl;
104     cout << "k1:" << k1 << endl;
105     cout << "&k1:" << &k1 << endl;
106     cout << "*k1:" << *k1 << endl;
107     cout << "k:" << k << endl;
108     cout << "&k:" << &k << endl;
109     cout << "*k:" << *k << endl;
110     cout << "**k:" << **k << endl;
111     cout << "***k:" << ***k << endl;
112 
113     cout<<"hello"<<endl;
114     system("pause");
115     return 0;
116 }