[C++] Type Conversion（类型转换）

Type Conversion（类型转换）

Two kinds of type conversion

• explict type conversion(显式类型转换)

• impict type conversion(隐式类型转换)

Two way to  convert type

• 赋值

• 构造函数

• 转换函数

转换函数

 

不支持friend

 

类与类转换

#include <iostream>

class mianji
{
public:
    friend class fushu;
    mianji()
    {
        this->cx = 0;
        this->cy = 0;
    }
    void setxy(int a,int b)
    {
        this->cx = a;
        this->cy = b;
    }
protected:
private:
    int cx;
    int cy;
};

class fushu
{
public:
    friend class mianji;//ÓÑÔª¿ÉÒÔ·ÃÎÊ˽ÓбäÁ¿
    fushu(mianji mianji1)
    {
        this->x = mianji1.cx;
        this->y = mianji1.cy;
    }
    void print()
    {
        std::cout << x << "+" << y << "i" << std::endl;
    }
    operator mianji()
    {
        mianji temp;
        temp.cx = x;
        temp.cy = y;
        return  temp;
    }

protected:
private:
    int x;
    int y;
};

void main()
{
    mianji  mianji1;
    fushu fushu1 =(fushu) mianji1;//通过构造函数转换
    fushu fushu1(mianji1);//通过构造函数转换
    
    mianji  mianji2;
    mianji2.setxy(10, 20);

    fushu1 = mianji2;//通过构造函数转换
    mianji2 = fushu1;//通过转换函数来转换
    fushu1.print();
    std::cin.get();
}