#include<iostream> using namespace std; class Triangle {public: Triangle (); void Triangle (float aa ,float bb ,float cc):a(aa),b(bb),c(cc)() float area(); private: float a; float b; float c; }; Triangle::Triangle(float aa,float bb,float cc) { if(a+b>c&&a+c>b&&b+c>a) {aa=a; bb=b; cc=c; } else {aa=0; bb=0; cc=0; cout<<"无法构成三角形"<<endl;} } Triangle::area() {return(a*b*c);} int main() {Triangle Triangle1; cout<<Triangle1.area()<<endl; Triangle box2(3,4,5); cout<<box2.area()<<endl; return 0; }这个程序哪里错了

这个程序有几个错误：

1.在类Triangle中，构造函数的声明和定义不匹配，应该是：

Triangle(float aa, float bb, float cc);

2.在构造函数中，赋值操作的顺序错误，应该是：

a = aa;
b = bb;
c = cc;

3.area()函数的返回值应该是一个浮点数，但是实际返回的是a,b,c的乘积，应该是：

float area() { float p = (a + b + c) / 2; return sqrt(p * (p - a) * (p - b) * (p - c)); }

4.main函数中创建Triangle对象时的参数不匹配，应该是：

Triangle Triangle1(0,0,0);

修改后的程序如下：

#include<iostream>
#include<cmath>
using namespace std;

class Triangle {
public:
    Triangle();
    Triangle(float aa, float bb, float cc);
    float area();

private:
    float a;
    float b;
    float c;
};

Triangle::Triangle(float aa, float bb, float cc) {
    if (aa + bb > cc && aa + cc > bb && bb + cc > aa) {
        a = aa;
        b = bb;
        c = cc;
    } else {
        a = 0;
        b = 0;
        c = 0;
        cout << "无法构成三角形" << endl;
    }
}

float Triangle::area() {
    float p = (a + b + c) / 2;
    return sqrt(p * (p - a) * (p - b) * (p - c));
}

int main() {
    Triangle Triangle1(0, 0, 0);
    cout << Triangle1.area() << endl;
    Triangle box2(3, 4, 5);
    cout << box2.area() << endl;
    return 0;
}