c++ 使用函数时函数调用缺少参数[关闭]

Question

void Circle::getXYr() {
    cout << "(x,y,R) = (" << x << "," << y << "," << r << ")" << endl;
}

double Circle::circArea() {
    return (r * r * PI);
}

double Circle::circPeri() {
    return (2 * r * PI);
}

void Circle::printCircle() {
    cout << "Printing circle " << getXYr << endl;
    cout << "Circle Area: " << circArea << endl;
    cout << "Circle Perimeter: " << circPeri << endl;
}

我无法使用 printCircle 函数：ERROR 错误 1 ​​错误 C3867: 'Circle::getXYr': function call missing argument list;使用 '&Circle::getXYr' 创建指向成员的指针

接下来的 2 个函数也一样。

Answer 1

它是函数，你必须这样调用它们。注意括号()

cout << "Printing circle " << this->getXYr() << endl;
cout << "Circle Area: " << this->circArea() << endl;
cout << "Circle Perimeter: " << this->circPeri() << endl;

this-> 不是明确需要的。

您的第二个错误是由于 this->getXYr() 没有返回值。它返回void。它没有 basic_ostream 重载。

您应该将 getXYr() 的逻辑放入 printCircle() 函数中。或者在不调用 cout 的情况下调用该函数：

cout << "Printing circle ";
this->getXYr();
cout << "Circle Area: " << this->circArea() << endl;
cout << "Circle Perimeter: " << this->circPeri() << endl;