參數和params用法在c + +

Question

我正在學習C++的類，我碰到這段代碼，我想知道什麼參數被用於。

// vectors: overloading operators example 
#include <iostream> 
using namespace std; 

class CVector { 
    public: 
    int x,y; 
    CVector() {}; 
    CVector (int,int); 
    CVector operator + (CVector); 
}; 

CVector::CVector (int a, int b) { 
    x = a; 
    y = b; 
} 

CVector CVector::operator+ (CVector param) { 
    CVector temp; 
    temp.x = x + param.x; 
    temp.y = y + param.y; 
    return (temp); 
} 

int main() { 
    CVector a (3,1); 
    CVector b (1,2); 
    CVector c; 
    c = a + b; 
    cout << c.x << "," << c.y; 
    return 0; 
} 

Answer 1

參數是+運算符的右操作數。

下面是代碼的清潔器版本：

#include <iostream> 
using namespace std; 

class CVector { 
    public: 
    int x,y; 
    CVector(); 
    CVector (int,int); 
    CVector (const CVector&); 
    CVector operator + (const CVector&) const; 
}; 

CVector::CVector() : x(0), y(0) {} 
CVector::CVector(int a, int b) : x(a), y(b) {} 
CVector::CVector(const CVector& v) : x(v.x), y(v.y) {} 

CVector CVector::operator+ (const CVector& param) const { 
    CVector temp(*this); 
    temp.x += param.x; 
    temp.y += param.y; 
    return (temp); 
} 

int main() { 
    CVector a (3,1); 
    CVector b (1,2); 
    CVector c; 
    c = a + b; 
    cout << c.x << "," << c.y; 
    return 0; 
} 

Answer 2

Param僅僅是一個標識符指定右邊的操作數OV重載+運算符。而不是它，你可以使用任何其他的標識符。

CVector a, b; 
a+b; //a is the object on which you call +, b is the param