class complex
{
public:
double real() const
{ return this->re; }
private:
double re, im;
};
一、non-static & static 區別
1.1non-static
complex c1,c2,c3;
cout<<c1.real();
cout<<c2.real();
會被編譯器自動轉化爲:
complex c1,c2,c3;
cout<<complex::real(&c1);
cout<<complex::real(&c2);
// c1,c2,c2 => this
non-static會被分成多塊內存,例如:
complex c1,c2,c3
- c1 => c1 not-static data member
- c2 => c2 not-static data member
- c3 => c3 not-static data member
通過this指向不同的內存!!!
1.2static
static僅僅分配一塊內存!!!
class Account
{
public:
static double m_rate;
static void set_rate(const double& x)
};
double Acount::m_rate = 8.0; // 假如設置了static必須要在外面定義,上面僅僅是聲明!!!
int main()
{
Acount::set_rate(5.0);
Acount a;
a.set_rate(7.0);
}
調用static函數的方式:
- 通過object調用
- 通過class name調用