c++操作符new 与delete学习

一，简单类型，new 一个int和new 一个int 数组

#include<stdio.h>
#include<stdlib.h>
#include<iostream>
 
//new 一个int
void main01()
{
	int num = 10;//栈上
	int *p = new int;
	*p = 5;
	std::cout << *p << " " << p << std::endl;
	delete p;
	std::cout << *p << " " << p << std::endl;
	system("pause");
}
 
//new 一个int 数组
void main02()
{
	int *p = new int[10];
	int i = 0;
 
	std::cout << p << std::endl;
 
	for (int i = 0; i < 10; i++)
	{
		p[i] = i;
		std::cout << p[i] << std::endl;
 
	}
 
	delete []p;
 
	std::cout << p << std::endl;
	system("pause");
 
}
 
//new 一个int 二维数组
void main04() {
	int *p = new int[80];
	int(*px)[10] = (int(*)[10])p; //强转
	int data = 0;
	for (int i = 0; i < 8; i++)
	{
		for (int j = 0; j < 10; j++)
		{
			px[i][j] = data++;
			std::cout << " " << px[i][j];
		}
		std::cout << std::endl;
	}
 
	system("pause");
 
}

二，new 与delete重载

#include <iostream>
 
class taosheng
{
public:
	static int jishuqi;//静态
	int *p;
	int length;
public:
	taosheng()
	{
		std::cout << "taosheng被创建了" << std::endl;
	}
	~taosheng()
	{
		std::cout << "taosheng被了销毁" << std::endl;
	}
	static void * operator new(size_t size)
	{
		jishuqi += 1;
		std::cout << "对象被创建了" << std::endl;
		taosheng *ptemp = ::new taosheng;
		return ptemp;
	}
	static void operator delete(void *p)
	{
		jishuqi -= 1;
		std::cout << "对象被了销毁" << std::endl;
		::delete p;
	}
};
 
int taosheng::jishuqi = 0;
 
void main()
{
	taosheng * p1 = new taosheng;
	taosheng * p2 = new taosheng;
	taosheng * p3 = new taosheng;
 
	delete p1;
	std::cout << taosheng::jishuqi << std::endl;
	system("pause");
}

二，对象数组的new 与 delete

#include <iostream>
 
class tansheng
{
	int *p;
	int length;
public:
	tansheng()
	{
		std::cout << "被创建了" << std::endl;
	}
	~tansheng()
	{
		std::cout << "不用了" << std::endl;
	}
};
 
void main001()
{
	tansheng *p =new tansheng;
	delete []p;
 
	system("pause");
}