Array class packaging case: To
implement a general array class, the requirements are as follows:
·Can store built-in data types and custom types of data
· Store the data in the array in the heap area
·The capacity
of the array can be passed into the constructor · Provide the corresponding copy constructor and operater= to prevent shallow copy problems
. Provide tail interpolation and tail deletion methods to add and delete data in the
array.
You can access the elements in the array by subscript . You can get the current element in the array. Number and capacity of array
#include <iostream>
using namespace std;
#include <string>
template<class T>
class MyArray
{
public:
//有参构造 参数 容量
MyArray(int capacity){
//cout << "MyArray 的构造函数调用" << endl;
this -> m_Capacity = capacity;
this -> m_Size = 0;
this -> pAddress = new T[this -> m_Capacity];
}
//拷贝构造函数
MyArray(const MyArray& arr){
//cout << "MyArray 的拷贝构造函数调用" << endl;
this -> m_Capacity = arr.m_Capacity;
this -> m_Size = arr.m_Size;
//this -> pAddress = arr.pAddress;
//深拷贝
this -> pAddress = new T[arr.m_Capacity];
//将arr中的数据都拷贝过来
for (int i = 0; i < this -> m_Size; i ++){
this -> pAddress[i] = arr.pAddress[i];
}
}
//operator= 防止浅拷贝问题 a = b =c
MyArray & operator= (const MyArray & arr){
//cout << "MyArray 的operator=函数调用" << endl;
//先判断原来堆区是否有数据，如果有先释放
if (this -> pAddress != NULL){
delete[] this -> pAddress;
this -> pAddress = NULL;
this -> m_Capacity = 0;
this -> m_Size = 0;
}
//深拷贝
this -> m_Capacity = arr.m_Capacity;
this -> m_Size = arr.m_Size;
this -> pAddress = new T[arr.m_Capacity];
for (int i = 0; i < this -> m_Size; i ++){
this -> pAddress[i] = arr.pAddress[i];
}
return *this;
}
void Push_Back(const T & val){
//判断容量是否等于大小
if (this -> m_Capacity == this -> m_Size){
cout << "容量已满" << endl;
return;
}
this -> pAddress[this -> m_Size] = val; //在数组末尾插入数据
this -> m_Size ++; //更新数组大小
}
void Pop_Back(){
//让用户访问不到最后一个元素，即为尾删，逻辑删除
if(this -> m_Size == 0){
cout << "容器已空" << endl;
return;
}
this -> m_Size --;
}
//通过下标方式访问数组中的元素 arr[0] = 10;&返回引用可以作为左值存在
T & operator[](int index){
return this -> pAddress[index];
}
//返回数组容量
int getCapacity(){
return this -> m_Capacity;
}
//返回数组大小
int getSize(){
return this -> m_Size;
}
//析构函数
~MyArray(){
if (this -> pAddress != NULL){
//cout << "MyArray 的析构函数调用" << endl;
delete[] this -> pAddress;
this -> pAddress = NULL;
}
}
private:
T * pAddress; //指针指向堆区开辟的真实数组
int m_Capacity; //数组容量
int m_Size; //
};
//################以下为测试代码#############
class Person
{
public:
Person(){
};
Person(string name, int age){
this -> m_Name = name;
this -> m_Age = age;
}
string m_Name;
int m_Age;
};
void printIntArray(MyArray<int> & arr){
for (int i = 0; i < arr.getSize(); i ++){
cout << arr[i] << endl;
}
}
void printPersonArray(MyArray<Person> & arr){
for (int i = 0; i < arr.getSize(); i ++){
cout << "姓名 : " << arr[i].m_Name << "年龄 : " << arr[i].m_Age << endl;
}
}
void test2()
{
MyArray<Person> arr(10);
Person p1("孙悟空", 999);
Person p2("猪八戒", 888);
Person p3("沙悟净", 777);
Person p4("白龙马", 666);
Person p5("唐三藏", 25);
arr.Push_Back(p1);
arr.Push_Back(p2);
arr.Push_Back(p1);
arr.Push_Back(p3);
arr.Push_Back(p4);
arr.Push_Back(p5);
printPersonArray(arr);
cout << arr.getCapacity() << endl;
cout << arr.getSize() << endl;
arr.Pop_Back();
printPersonArray(arr);
cout << arr.getCapacity() << endl;
cout << arr.getSize() << endl;
}
void test()
{
MyArray<int> arr1(5);
for (int i = 0; i < 5; i ++){
arr1.Push_Back(i);
}
cout << "arr1的打印输出" << endl;
printIntArray(arr1);
cout << "arr1的rongliang : " << arr1.getCapacity() << endl;
cout << "arr1的rongliangde daxiao : " << arr1.getSize() << endl;
MyArray<int> arr2(arr1);
arr2.Pop_Back();
cout << "arr2尾删后的打印输出" << endl;
cout << "arr2的rongliang : " << arr2.getCapacity() << endl;
cout << "arr2的rongliangde daxiao : " << arr2.getSize() << endl;
//MyArray<int> arr3(100);
//arr3 = arr1;
}
int main(){
test2();
test();
system("pause");
}
Dark horse programmer C++ course case exercises