C++面向对象之类和对象那些你不知道的细节原理详解

class SeqStack
{

public:
	SeqStack(int size = 10) :_top(-1), _size(size) {
		_pstack = new int[size];
	}
	~SeqStack() {
		cout << this << "~SeqStack()" << endl;
		delete[] _pstack;
		_pstack = nullptr;
	}

	void push(int val) {
		if (full()) {
			resize();
		}
		_pstack[++_top] = val;
	}

	void pop() {
		if (empty()) {
			return;
		}
		--_top;
	}

	int top() {
		return _pstack[_top];
	}
	bool empty() { return _top == -1; }
	bool full() { return _top == _size-1; }

private:
	int* _pstack;

	int _top;

	int _size;

	void resize() {
		int* ptmp = new int[_size * 2];
		for (int i = 0; i < _size; i++) {
			ptmp[i] = _pstack[i];
		}
		delete[] _pstack;
		_pstack = ptmp;
		_size *= 2;
	}
};

int main() {
	SeqStack sq1;

	for (int i = 0; i < 15; i++) {
		sq1.push(rand() % 100);
	}

	while (!sq1.empty()) {
		cout << sq1.top() << " ";
		sq1.pop();
	}

	return 0;
}

	SeqStack& operator=(const SeqStack& src) {
		cout << "operator=" << endl;
		//防止自赋值
		if (this == &src) {
			return *this;
		}
		delete[] _pstack;//需要释放掉自身占用的外部资源
		_pstack = new int[src._size];
		for (int i = 0; i <= src._top; i++) {
			_pstack[i] = src._pstack[i];
		}
		_top = src._top;
		_size = src._size;
		return *this;
	}

	SeqStack(const SeqStack& src) {
		cout << this << "SeqStack(const SeqStack& src)" << endl;
		_pstack = new int[src._size];
		for (int i = 0; i <= src._top; i++) {
			_pstack[i] = src._pstack[i];
		}
		_top = src._top;
		_size = src._size;
	}

#pragma once
class CirQueue
{
public:
	CirQueue(int size = 10) {
		_pQue = new int[size];
		_front = _rear = 0;
		_size = size;
	}

	CirQueue(const CirQueue& src) {
		_size = src._size;
		_front = src._front;
		_rear = src._rear;
		_pQue = new int[_size];
		for (int i = _front; i != _rear; i = (i + 1) % _size) {
			_pQue[i] = src._pQue[i];
		}
	}

	~CirQueue() {
		delete[] _pQue;
		_pQue = nullptr;
	}

	CirQueue& operator=(const CirQueue& src) {
		if (this == &src) {
			return *this;
		}
		delete[] _pQue;//需要释放掉自身占用的外部资源
		_size = src._size;
		_front = src._front;
		_rear = src._rear;
		_pQue = new int[_size];
		for (int i = _front; i != _rear; i = (i + 1) % _size) {
			_pQue[i++] = src._pQue[i];
		}
		return *this;
	}

	void push(int val) {
		if (full()) {
			resize();
		}
		_pQue[_rear] = val;
		_rear = (_rear + 1) % _size;
	}
	void pop() {
		if (empty()) {
			return;
		}
		_front = (_front + 1) % _size;
	}

	int front() {
		return _pQue[_front];
	}

	bool full() {
		return (_rear + 1) % _size == _front;
	}
	
	bool empty () {
		return _front == _rear;
	}

private:
	int* _pQue;

	int _front;

	int _rear;

	int _size;

	void resize() {
		int* ptmp = new int[_size * 2];
		int index = 0;
		for (int i = _front; i != _rear; i=(i+1)%_size) {
			ptmp[index++] = _pQue[i];
		}
		delete[] _pQue;
		_pQue = ptmp;
		_front = 0;
		_rear = index;
		_size *= 2;
	}
};

#pragma once
#include <algorithm>
class String
{
public:

	String(const char* str = nullptr) {
		if (str != nullptr) {
			_pChar = new char[strlen(str) + 1];
			strcpy(_pChar, str);
		}
		else {
			_pChar = new char[1];
			*_pChar = '\0';
		}
	}

	String(const String& str) {
		_pChar = new char[strlen(str._pChar)+1];
		strcpy(_pChar, str._pChar);
	}

	~String() {
		delete[] _pChar;
		_pChar = nullptr;
	}

	String& operator=(const String& str) {
		if (this == &str) {
			return *this;
		}
		delete[] _pChar;//需要释放掉自身占用的外部资源

		_pChar = new char[strlen(str._pChar) + 1];
		strcpy(_pChar, str._pChar);
		return *this;
	}

private:
	char* _pChar;
	
};

class Test {
public:
	void func() { cout << "call Test::func" << endl; }
	static void static_func() { cout << "call Test::static_func" << endl; }

	int ma;
	static int mb;
};

int Test::mb=0;

int main() {
	Test t1;
	Test *t2 = new Test();//在堆上生成对象，并用指针指向

	//使用指针调用类成员方法(前面要加类的作用域Test::)
	void (Test:: * pfunc)() = &Test::func;
	(t1.*pfunc)();
	(t2->*pfunc)();

	//定义指向static的类成员方法
	void(*pfunc1)() = &Test::static_func;
	(*pfunc1)();

	//使用指针指向类成员变量，前面要加类的作用域Test::
	int Test::* p = &Test::ma;
	t1.*p = 20;
	cout << t1.*p << endl;

	t2->*p = 30;
	cout << t2->*p << endl;

	int* p1 = &Test::mb;
	*p1 = 40;
	cout << *p1 << endl;

	delete t2;
	return 0;
}