[数据结构与算法]c++上机6

#include<iostream>
#include<string>
 
using namespace std;
class MyArray {
 
public:
 
	MyArray(int length);
	~MyArray();
	void Input();
 
	void Display(string);
protected:
 
	int* alist;
 
	int length;
 
};
 
MyArray::MyArray(int leng)
{
	
	if (leng <= 0)
	{
		cout << "error length";
		exit(1);
	}
    length = leng;
	alist = new int[length];
 
	if (alist == NULL)
	{
		cout << "assign failure";
		exit(1);
	}
	cout<<"MyArrayl类对象已创建!" << endl;
}
 
MyArray::~MyArray()
{
	delete[] alist;
 
	cout << "MyArray类对象已撤销!"<< endl;
 
}
 
void MyArray::Display(string str)
{
	int i;
 
	int* p = alist;
 
	cout << str << length << "个整数: ";
	for (i = 0; i < length; i++, p++)
		cout << *p << "";
	cout << endl;
}
 
void MyArray::Input()
{
	cout << "请从键盘输入" << length << "个整数:";
	int i;
 
	int* p = alist;
 
	for (i = 0; i < length; i++, p++)
 
		cin >> *p;
}
 
int main()
{
 
	MyArray a(5);
 
	a.Input();
 
	a.Display("显示已经输入的");
 
	return 0;
 
}

运行结果：

#include<iostream>
#include<string>
using namespace std;
class MyArray {
public:
	MyArray(int length);
	~MyArray();
	void Input();
	void Display(string);
protected:
	int* alist;
	int length;
};
class SortArray :public MyArray
{
public:
	SortArray(int leng) :MyArray(leng)
	{
		cout << "SortArray类对象已创建！" << endl;
	}
	~SortArray()
	{
		cout << "SortArray类对象已销毁！" << endl;
	}
	void sort()
	{
		int i, k, temp;
		int* p = alist;      
		cout << "显示排序以后的5个整数：";
		for (i = 0; i < length - 1; i++)    
			for (k = i + 1; k < length; k++)
			{
				if (*(alist + i) > *(alist + k))
				{
					temp = *(alist + i);
					*(alist + i) = *(alist + k);
					*(alist + k) = temp;
				}
			}
		for (i = 0; i < length; i++, p++)
		{
			cout << *p << " ";
		}
		cout << endl;
	}
}; 
MyArray::MyArray(int leng) {
	if (leng <= 0)
	{
		cout << "error length";
		exit(1);
	}
	length = leng;
	alist = new int[length];
	if (alist == NULL)
	{
		cout << "assign failure";
		exit(1);
	}
	cout << "MyArrayl类对象已创建!" << endl;
}
MyArray::~MyArray()
{
	delete[] alist;
	cout << "MyArray类对象已撤销!" << endl;
}
void MyArray::Display(string str)
{
	int i;
	int* p = alist;
	cout << str << length << "个整数: ";
	for (i = 0; i < length; i++, p++)
		cout << *p << "";
	cout << endl;
}
void MyArray::Input()
{
	cout << "请从键盘输入" << length << "个整数:";
	int i;
	int* p = alist;
	for (i = 0; i < length; i++, p++)
		cin >> *p;
}
int main()
{
	SortArray a(5);
	a.Input();
	a.Display("显示已经输入的");
	a.sort();
	return 0; 
}

运行结果：

总结：

派生类构造函数和析构函数的执行顺序：
? ? ?创建派生类对象时，先执行基类的构造函数，然后再执行派生类的构造函数；当撤销派生类对象时，先执行派生类的析构函数，再执行基类的析构函数。

构造函数的执行顺序是：先调用基类构造函数，后调用派生类的构造函数，析构函数的调用顺序和构造函数的调用顺序正好相反。