《Essential C++》系列笔记之第四章(基于对象的编程风格)之第一节(如何实现一个Class)

代码实践

• main.cpp

  #include 
  using namespace std;
  #include "Stack.h"
  
  int main()
  {
  	//class stack; //提供了一个前置声明 下面两句才可以使用
  	//stack* pa = 0;
  	//void process(const stack & s); 
  
  	//练习4_1
  #if 0
  
  	Stack stack;
  	cout << "----------" << endl;
  	cout << "size: " << stack.size() << endl;
  	cout << "empty: " << stack.empty() << endl;
  	cout << "full: " << stack.full() << endl;
  	string hi;
  	cout << "pop: " << stack.pop(hi) << endl;
  	cout << "peek: " << stack.peek(hi) << endl;
  	cout << "hi: " << hi << endl;
  	cout << "-----------" << endl;
  
  	cout << "push: " << stack.push("Hello");
  	cout << "push: " << stack.push("Class");
  	cout << "push: " << stack.push("!");
  
  	cout << "size: " << stack.size() << endl;
  	cout << "empty: " << stack.empty() << endl;
  	cout << "full: " << stack.full() << endl;
  	cout << "peek: " << stack.peek(hi) << endl;
  	cout << "hi: " << hi << endl;
  	cout << "pop: " << stack.pop(hi) << endl;
  	cout << "peek: " << stack.peek(hi) << endl;
  	cout << "hi: " << hi << endl;
  #endif
  
  	练习4_2
  #if 1
  	Stack stack;
  	string hi;
  	cout << "push Hello: " << stack.push("Hello") << ' ';
  	cout << "push Class: " << stack.push("Class") << ' ';
  	cout << "push !: " << stack.push("!") << endl;
  	cout << "size: " << stack.size() << endl;
  	cout << "empty: " << stack.empty() << endl;
  	cout << "full: " << stack.full() << endl;
  	cout << "peek: " << stack.peek(hi) << endl;
  	cout << "peek hi: " << hi << endl;
  	cout << "pop: " << stack.pop(hi) << endl;
  	cout << "peek: " << stack.peek(hi) << endl;
  	cout << "hi: " << hi << endl;
  	cout << "find Hello: " << stack.find("Hello") << endl;
  	cout << "find World: " << stack.find("World") << endl;
  	cout << "count Hello: " << stack.count("Hello") << endl;
  	cout << "count World: " << stack.count("World") << endl;
  
  #endif
  
  	system("pause");
  	return 0;
  }
  

• Stack.h

  #pragma once
  #include 
  #include 
  #include 
  #include 
  using namespace std;
  
  class Stack
  {
  public:
  	bool push(const string&);
  	bool pop(string&);
  	bool peek(string&);
  	bool find(const string&);
  
  	bool empty();
  	bool full();
  	
  	int size()
  	{
  		return _stack.size();
  	}
  	int count(const string&);
  
  private:
  	vector<string> _stack;
  };
  
  inline bool Stack::empty()
  {
  	return _stack.empty();
  }
  
  inline bool Stack::full()
  {
  	return _stack.size() == _stack.max_size();
  }
  

• Stack.cpp

  #include "Stack.h"
  
  bool Stack::push(const string& elem)
  {
  	if (full())
  	{
  		return false;
  	}
  	
  	_stack.push_back(elem);
  	return true;
  }
  
  bool Stack::peek(string& elem)
  {
  	if (empty())
  	{
  		return false;
  	}
  
  	elem = _stack.back();
  	return true;
  }
  
  bool Stack::pop(string& elem)
  {
  	if (empty())
  	{
  		return false;
  	}
  
  	elem = _stack.back();
  	_stack.pop_back();
  	return true;
  }
  
  bool Stack::find(const string& elem)
  {
  	/*vector::iterator it = _stack.begin();
  
  	for (; it != _stack.end(); it++)
  	{
  		if (*it == elem)
  		{
  			return true;
  		}
  	}
  	return false;*/
  	//注意这里的::的作用
  	return (::find(_stack.begin(), _stack.end(), elem) != _stack.end());
  }
  
  int Stack::count(const string& elem)
  {
  	/*if (!find(elem))
  	{
  		return 0;
  	}
  
  	int cnt = 0;
  	vector::iterator it = _stack.begin();
  	for (; it != _stack.end(); it++)
  	{
  		if (*it == elem)
  		{
  			cnt++;
  		}
  	}
  	return cnt;*/
  	return ::count(_stack.begin(), _stack.end(), elem);
  }
  
  
  

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