c++操作符new 与delete学习

朱雀 2023-01-24 04:26 79阅读 0赞

### 文章目录 ###

*  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
     *  二，new 与delete重载
     *  二，对象数组的new 与 delete
 *  参考

# 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");
    }

注意，重载

## 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");
    }

# 参考 #

[delete 和 delete \[\]的真正区别][delete _ delete]  
[浅谈 C++ 中的 new/delete 和 new\[\]/delete\[\]][C_ _ new_delete _ new_delete]  
[必看–C/C++返回内部静态成员的陷阱][C_C]

[delete _ delete]: https://blog.csdn.net/cbnotes/article/details/38900799?readlog
[C_ _ new_delete _ new_delete]: https://blog.csdn.net/hazir/article/details/21413833
[C_C]: https://blog.csdn.net/haoel/article/details/1388498