const
初始化const成员变量使用初始化列表
class AA
{
private:
int const m_a;
int m_b;
public:
AA():m_a(100) //类中只能用初始化列表初始const变量
{
}
void show ()const;
};#include<iostream>
using namespace std;
class AA
{
private:
int const m_a;
int m_b;
public:
AA():m_a(100) //类中只能用初始化列表初始const变量
{
}
void show ()const;
};
void AA::show (/*const AA * const this*/)const // 常函数不能修改成员变量
{
m_b=20;
}
int main()
{
const AA a;
a.show();// 常对象只能使用常函数
system("pause");
return 0;
}函数前加const标识返回值类型为const 函数后加表示为常函数????????
class和struct
struct在c++中可以有成员函数
struct AA
{
int a;
AA()
{
a=100;
}
~AA()
{
};
};
string?
#include<iostream>
using namespace std;
int main()
{
char *str=new char[10];
strcpy_s(str,10,"abcde");
str[1]='B';
system("pause");
return 0;
}
?类之间的关系
1 、组合
????????
#include<iostream>
using namespace std;
class Head
{
public:
void say()
{
cout<<"说话"<<endl;
}
};
class Hand
{
public:
void move()
{
cout<< "比划"<<endl;
}
};
class person
{
private:
Head m_head;
Hand m_hand;
public:
void meeting()
{
cout<<"开会了"<<endl;
this->m_head.say();
this->m_hand.move();
}
};
int main()
{
person per;
per.meeting();
system("pause");
return 0;
}
?2 依赖
?
#include<iostream>
using namespace std;
class computer
{
public:
void code()
{
cout<<"#include<iostream>...."<<endl;
}
};
class person
{
public:
void coding(computer &cp)
{
cout<<"打代码"<<endl;
cp.code();
}
};
int main()
{
computer cp;
person per;
per.coding(cp);
system("pause");
return 0;
}
?