C++的泛型编程方式

 1 #pragma once
 2 
 3 template<class T>
 4 class MyArray
 5 {
 6 public:
 7     //有参构造
 8     MyArray(int capacity)
 9     {
10         mCapacity = capacity;
11         mSize = 0;
12         pAdress = new T[mCapacity];
13     }
14     //拷贝构造
15     MyArray(const MyArray& my1)
16     {
17         this->mCapacity = my1.mCapacity;
18         this->mSize = my1.mSize;
19         this->pAdress = new T[mCapacity];
20         for (int i = 0; i < mSize; i++)
21             pAdress[i] = my1.pAdress[i];
22     }
23     //重载等号操作符
24     MyArray& operator=(const MyArray& my1)
25     {
26         if (this->pAdress != NULL)
27         {
28             delete[] pAdress;
29             this->pAdress = NULL;
30         }
31         this->mCapacity = my1.mCapacity;
32         this->mSize = my1.mSize;
33         this->pAdress = new T[mCapacity];
34         for (int i = 0; i < mSize; i++)
35             pAdress[i] = my1.pAdress[i];
36         return *this;
37     }
38     //重载[]号操作符
39     T& operator[](int index)
40     {
41         return this->pAdress[index];
42     }
43 
44     //尾插法
45     void pushBack(T val)
46     {
47         if (mSize == mCapacity)
48             return;
49         pAdress[mSize] = val;
50         mSize++;
51     }
52     //尾部删除法
53     void popBack()
54     {
55         mSize--;
56     }
57     ~MyArray()
58     {
59         if (this->pAdress)
60         {
61             delete[] pAdress;
62             pAdress = NULL;
63             mCapacity = 0;
64             mSize = 0;
65         }
66     }
67 
68 
69 private:
70     T* pAdress;            //指向数组的指针
71     int mCapacity;
72     int mSize;    
73 };

 1 //普通类型
 2 void test021()
 3 {
 4     MyArray<char> arr(10);
 5     for (char i = ‘a‘; i <= ‘j‘; i++)　　　　//给数组赋值
 6         arr.pushBack(i);
 7     for (int i = 0; i < 10; i++)
 8         cout << arr[i]<<"  ";
 9 }
　　//自定义的类型
10 class person
11 {
12 public:
13     person()
14     {
15         this->mName = new char[strlen("undefined!") + 1];
16         strcpy(this->mName, "undefined!");
17         mAge = -1;
18     }
19     //有参构造
20     person(char *name, int age)
21     {
22         mName = new char[strlen(name) + 1];
23         strcpy(mName, name);
24         mAge = age;
25     }
26     //拷贝构造
27     person(const person& p1)
28     {
29         mName = new char[strlen(p1.mName) + 1];
30         strcpy(mName, p1.mName);
31         mAge = p1.mAge;
32     }
33 
34     //重载等号操作符
35     person& operator=(const person& p1)
36     {
37         if (mName != NULL)
38         {
39             delete[] mName;
40             mName = NULL;
41         }
42         mName = new char[strlen(p1.mName) + 1];
43         strcpy(mName, p1.mName);
44         mAge = p1.mAge;
45         return *this;
46     }
47     ~person()
48     {
49         if (mName)
50         {
51             delete[] mName;
52             mName = NULL;
53         }
54     }
55 public:
56     char *mName;
57     int mAge;
58 };
59 
60 
61 //自定义类型
62 void test022()
63 {
64     //自定义类型做数组元素时，类型必须提供默认无参构造函数。
65     MyArray<person> arr(10);
66 
67     person p1("john1", 19);
68     person p2("john2", 29);
69     person p3("john3", 39);
70     person p4("john4", 49);
71     person p5("john5", 59);
72 
73     arr[1] = p1;
74     arr.pushBack(p2);
75     cout << "Name:" << arr[0].mName << " Age:" << arr[0].mAge << endl;
76     arr.pushBack(p3);
77     cout << "Name:" << arr[1].mName << " Age:" << arr[1].mAge << endl;
78 
79 }