//12_1.cpp #include <iostream> using namespace std; int divide(int x, int y) { if (y == 0) throw x; return x / y; } int main() { try { cout << "5 / 2 = " << divide(5, 2) << endl; cout << "8 / 0 = " << divide(8, 0) << endl; cout << "7 / 1 = " << divide(7, 1) << endl; } catch (int e) { cout << e << " is divided by zero!" << endl; } cout << "That is ok." << endl; return 0; }
可以在函数的声明中列出这个函数可能抛掷的所有异常类型。
例如：void fun() throw(A，B，C，D);
若无异常接口声明，则此函数可以抛掷任何类型的异常。
不抛掷任何类型异常的函数声明如下：
void fun() throw();
//12_2.cpp #include <iostream> #include <string> using namespace std; class MyException { public: MyException(const string &message) : message(message) {} ~MyException() {} const string &getMessage() const { return message; } private: string message; }; class Demo { public: Demo() { cout << "Constructor of Demo" << endl; } ~Demo() { cout << "Destructor of Demo" << endl; } }; void func() throw (MyException) { Demo d; cout << "Throw MyException in func()" << endl; throw MyException("exception thrown by func()"); } int main() { cout << "In main function" << endl; try { func(); } catch (MyException& e) { cout << "Caught an exception: " << e.getMessage() << endl; } cout << "Resume the execution of main()" << endl; return 0; } 运行结果： In main function Constructor of Demo Throw MyException in func() Destructor of Demo Caught an exception: exception thrown by func() Resume the execution of main()
编写一个计算三角形面积的函数，函数的参数为三角形三边边长a、b、c，可以用Heron公式计算：
//12_3.cpp #include <iostream> #include <cmath> #include <stdexcept> using namespace std; //给出三角形三边长，计算三角形面积 double area(double a, double b, double c) throw (invalid_argument) { //判断三角形边长是否为正 if (a <= 0 || b <= 0 || c <= 0) throw invalid_argument("the side length should be positive"); //判断三边长是否满足三角不等式 if (a + b <= c || b + c <= a || c + a <= b) throw invalid_argument("the side length should fit the triangle inequation"); //由Heron公式计算三角形面积 double s = (a + b + c) / 2; return sqrt(s * (s - a) * (s - b) * (s - c)); } int main() { double a, b, c; //三角形三边长 cout << "Please input the side lengths of a triangle: "; cin >> a >> b >> c; try { double s = area(a, b, c); //尝试计算三角形面积 cout << "Area: " << s << endl; } catch (exception &e) { cout << "Error: " << e.what() << endl; } return 0; } • 运行结果1： Please input the side lengths of a triangle: 3 4 5 Area: 6 • 运行结果2： Please input the side lengths of a triangle: 0 5 5 Error: the side length should be positive • 运行结果2： Please input the side lengths of a triangle: 1 2 4 Error: the side length should fit the triangle inequation
原文：https://www.cnblogs.com/aidata/p/13042022.html