第10课 C++异常简介

#include <iostream>

using namespace std;

double divide(double a, double b)
{
    const double delta = 0.000000000000001;
    double ret = 0;

    if( !((-delta < b) && ( b < delta))){
        ret = a / b;
    }else{
        throw 0; //产生除0异常
    }

    return ret;
}

//匹配规则（自上而下，严格匹配、不进行类型转换）
void Demo1()
{
    try{
        throw 'c';  //抛出字符型的异常
    }catch(int i){
        cout << "catch(int i)" << endl;
    }catch(double d){
        cout << "catch(double d)" << endl;
    }catch(char c){ //只能被这里的catch捕获
        cout << "catch(char c)" << endl;
    }
}

void Demo2()
{
    throw "Demo2";   //const char*
}
int main()
{
    cout << "main() begin" << endl;

    try{
        double c = divide(1, 0);//产生异常
        cout <<"c = " << c << endl; //无法被执行到！
    }catch(...){
        cout << "Divide by zero..." << endl;
    }

    Demo1();

    try{
        Demo2();
    }catch(char* c){
        cout << "catch(char* c)" << endl;
    }catch(const char* c){
        cout << "catch(const char* c)" << endl;
    }catch(...){
        cout << "catch(...)" << endl;
    }

    cout << "main() end" << endl;
    return 0;
}
/*输出结果
main() begin
Divide by zero...
catch(char c)
catch(const char* c)
main() end
*/