第八章

来源：互联网发布：关于地域歧视知乎编辑：程序博客网时间：2024/04/28 13:30

#include <iostream>#include <cmath>using namespace std;double q(double,double,double);void main(){double a,b,c,p,x1,x2; cout<<"please enter a,b,c:"; cin>>a>>b>>c; p=-b/(2*a); try  {x1=p+q(a,b,c);   x2=p-q(a,b,c);   cout<<"x1="<<x1<<endl<<"x2="<<x2<<endl;  } catch(double d)   {cout<<"a="<<a<<",b="<<b<<",c="<<c<<",disc="<<d<<",error!"<<endl;} cout<<"end"<<endl;}double q(double a,double b,double c) {double disc;  disc=b*b-4*a*c;  if (disc<0) throw disc;  return sqrt(disc)/(2*a); }

#include <iostream>#include <string>using namespace std;class Student {public:   Student(int n,string nam)     {cout<<"constructor-"<<n<<endl;     num=n;name=nam;}   ~Student(){cout<<"destructor-"<<num<<endl;}   void get_data();private:   int num;   string name; };void Student::get_data() {if(num==0) throw num;  else cout<<num<<" "<<name<<endl;  cout<<"in get_data()"<<endl; }void fun(){Student stud1(1101,"tan"); stud1.get_data(); try  {Student stud2(0,"Li");   stud2.get_data();  } catch(int n)  {cout<<"num="<<n<<",error!"<<endl;}}int main(){cout<<"main begin"<<endl; cout<<"call fun()"<<endl; fun(); cout<<"main end"<<endl; return 0;}

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