c++学习例程（2）类的使用

1样例

创建一个栈类，用来保存数据和删除

 

 

 

 CMakeLists.txt

cmake_minimum_required(VERSION 3.10)

project(Stack_Test)

#1手动设置指定文件
#set(Current_LIST main.cpp)

#2自动搜所文件目录
aux_source_directory(. Current_LIST) # 搜索当前.目录下的所有.cpp文件
aux_source_directory(./src SRC_LIST) # 搜索当前.目录下的所有.cpp文件

include_directories(src)#关键 不是相对引用 需要单独制定包含

# 4指定生成目标
add_executable(Stack_demo ${Current_LIST} ${SRC_LIST})

　　main.cpp

#ifndef MAIN_CPP
#define MAIN_CPP

//#include "API_stack.h"  //关键地方 不是相对引用 src/API_Cout.h cmakelist.txt需要加包含文件include_directories
#include "src/API_stack.h"  //关键地方 相对引用 src/API_Cout.h cmakelist.txt不需要加包含文件include_directories

#include <iostream>
#include <cctype>

using namespace std;

int main()
{

    Stack st;
    char ch;
    unsigned long po;

    cout<<"paleas enter A to add a data \n"
             <<"P to pop a data \n"
             <<"Q to quit"<<endl;

    while(cin >> ch && toupper(ch) != 'Q') //等待输入 且不为Q 退出
    {
        while(cin.get() != '\n')//等待回车确认 换行符号
            continue;

        if(!isalpha(ch))//检查c是否为字母。
        {
            cout<< '\a'<<"input is not char "<<endl; //凤鸣报警
            continue;
        }


        switch(ch)
        {
            case 'A':
                cout<< "enter a number to add";
                cin>> po;
                if(st.isfull())
                    cout<< "stack already full\n"<<endl;
                else
                {
                    st.push(po);
                }
                break;
            case 'P':
                if(st.isempty())
                    cout<<"stack alread empty"<<endl;
                else
                {
                    st.pop(po);
                    cout<<"Po "<< po<<"popped\n";
                }
                break;
        }
        cout<<"paleas enter A to add a data \n"
                <<"P to pop a data \n"
                <<"Q to quit"<<endl;

    }

    cout<<"Bye" <<endl;
    return 0;
}

#endif 

　　

 

 API_stack.h

#ifndef STACK_H
#define STACK_H


#include <string>
#include <iostream>

typedef unsigned long Item;

class Stack
{
    private:
        enum{MAX=10};
        Item items[MAX];
        int top;
    public:
        Stack();
        ~Stack();
        bool isempty() const;
        bool isfull() const;
        bool push(const Item &item);
        bool pop(Item &item);

};




#endif

　　API_stack.cpp

#ifndef STACK_CPP
#define STACK_CPP

#include "API_stack.h"


Stack::Stack()
{
    top=0;
}

Stack::~Stack()
{
    using namespace std;
    cout<<"class is over"<<endl;
}

bool Stack::isempty() const
{
    return top==0;
}

bool Stack::isfull() const
{
    return top==MAX;
}

bool Stack::push(const Item &item)
{
    if(top<MAX)
    {
        items[top++]=item;
        return true;
    }
    else
    {
        return false;
    }
}

bool Stack::pop(Item &item)
{
    if(top >0)
    {
        item=items[--top];
        return true;
    }
    else
        return false;
}




#endif

　　

编译

cd build
cmake ..
make
./Stack_demo