c++学习笔记

一、c++是一门面对对象的编程语言，按照封装的原则，一般情况下其数据成员设置为私有成员也即是（private）,那么我们怎么样去访问或者应用私有成员呢？

1、利用公共函数访问私有成员

#include<iostream>
using namespace std;
class MyTest
{
private:
int data1;
int data2;
public:
void setdata1(int x)
{
data1 = x;
}
void setdata2(int y)
{
data2 = y;
}
void display()
{
cout << "x=" << data1 << " " << "y=" << data2<<endl;
}
};

int main()
{
MyTest T;
T.setdata1(2);
T.setdata2(3);
T.display();

return 0;
}

2、利用指针访问私有成员

#include<iostream>
using namespace std;
class MyTest
{
private:
int data1;
int data2;
public:
void setdata1(int x)
{
data1 = x;
}
void setdata2(int y)
{
data2 = y;
}
void getxy(int *x, int *y)
{
*x = data1;
*y = data2;
}
};

int main()
{
MyTest T;
int x, y;
T.setdata1(2);
T.setdata2(3);
T.getxy(&x, &y);
cout << "x=" <<x << " " << "y=" << y << endl;

return 0;
}

3、利用设置函数访问私有成员

#include<iostream>
using namespace std;
class MyTest
{
private:
int data1;
int data2;
public:
int setdata1(int x)
{
data1 = x;
return data1;
}
int setdata2(int y)
{
data2 = y;
return data2;
}
};

int main()
{
MyTest T;
int x, y;
x=T.setdata1(2);
y=T.setdata2(3);
cout << "x=" <<x << " " << "y=" << y << endl;

return 0;
}