014：MyString 

 1 #include <iostream>
 2 #include <string>
 3 #include <cstring>
 4 using namespace std;
 5 class MyString {
 6     char * p;
 7 public:
 8     MyString(const char * s) {
 9         if( s) {
10             p = new char[strlen(s) + 1];
11             strcpy(p,s);
12         }
13         else
14             p = NULL;
15 
16     }
17     ~MyString() { if(p) delete [] p; }
18 MyString(const MyString& x) {
19         if (x.p) {
20             p = new char[strlen(x.p + 1)];
21             strcpy(p, x.p);
22         }
23         else
24             p = NULL;
25     }
26     MyString() {
27 
28     }
29     void Copy(const char* str) {
30         if (str) {
31             p = new char[strlen(str) + 1];
32             strcpy(p, str);
33         }
34         else p = NULL;
35     }
36     MyString& operator =(const MyString& x) {
37         if (p == x.p) return *this;
38         if (p)delete[]p;
39         if (x.p) {
40             p = new char[strlen(x.p) + 1];
41             strcpy(p, x.p);
42         }
43         else p = NULL;
44 
45         return *this;
46     }
47 
48     friend ostream& operator <<(ostream& os, const MyString& x) {
49         os << x.p;
50         return os;
51     }
52 
53 };
54 int main()
55 {
56     char w1[200],w2[100];
57     while( cin >> w1 >> w2) {
58         MyString s1(w1),s2 = s1;
59         MyString s3(NULL);
60         s3.Copy(w1);
61         cout << s1 << "," << s2 << "," << s3 << endl;
62 
63         s2 = w2;
64         s3 = s2;
65         s1 = s3;
66         cout << s1 << "," << s2 << "," << s3 << endl;
67         
68     }
69 }

 

 1 #include <iostream>
 2 #include <string>
 3 #include <cstring>
 4 using namespace std;
 5 class MyString {
 6     char * p;
 7 public:
 8     MyString(const char * s) {
 9         if( s) {
10             p = new char[strlen(s) + 1];
11             strcpy(p,s);
12         }
13         else
14             p = NULL;
15 
16     }
17     ~MyString() { if(p) delete [] p; }
18  MyString(const MyString& s){
19         if(s.p){
20             p = new char[strlen(s.p) + 1];
21             strcpy(p,s.p);
22         }
23         else
24             p = NULL;
25     } 
26     void Copy(const char* s){
27         if( s) {
28             p = new char[strlen(s) + 1];
29             strcpy(p,s);
30         }
31         else
32             p = NULL;
33     }
34     friend ostream& operator<<(ostream& o,const MyString& s){
35         o << s.p;
36         return o;
37     }
38     MyString& operator=(const MyString& s){
39         if(s.p == p) return *this;//!!!很重要,删了后面就没复制的了 
40         if(p) delete []p; 
41         if(s.p){
42             p = new char[strlen(s.p) + 1];
43             strcpy(p,s.p);
44         }
45         else
46             p = NULL;
47         return *this;
48     }
49 };
50 int main()
51 {
52     char w1[200],w2[100];
53     while( cin >> w1 >> w2) {
54         MyString s1(w1),s2 = s1;
55         MyString s3(NULL);
56         s3.Copy(w1);
57         cout << s1 << "," << s2 << "," << s3 << endl;
58 
59         s2 = w2;
60         s3 = s2;
61         s1 = s3;
62         cout << s1 << "," << s2 << "," << s3 << endl;
63         
64     }
65 }

posted @ 2022-09-13 22:35  balabalahhh  阅读(50)  评论(0)    收藏  举报