C/C++中异常处理详解及其作用介绍

#include <iostream>
using namespace std;

template <typename T>
T Div(T x, T y);

int main() {
    // 声明变量
    int x, y;
    double x1, y1;

    // 赋值
    cin >> x >> y;
    cin >> x1 >> y1;

    // 输出商
    cout << x << "/" << y << "=" << Div(x, y) << endl;
    cout << x1 << "/" << y1 << "=" << Div(x1, y1) << endl;

    return 0;
}

template <typename T>
T Div(T x, T y) {
    return x / y;
}

try {
    被检查语句
    throw 异常
}
catch(异常类型1) {
    进行异常处理的语句1
}
catch(异常类型2) {
    进行异常处理的语句2
}

double triangle(double,double,double) throw();

int triangle(int a, int b, int c) throw(runtime_error);

#include <iostream>
using namespace std;

template <typename T>
T Div(T x, T y);

int main() {
    // 声明变量
    int x, y;
    double x1, y1;

    // 赋值
    cout << "Please enter two int:\n";
    cin >> x >> y;
    cout << "Please enter two double:\n";
    cin >> x1 >> y1;

    try {
        // 被检查的语句
        cout << x << "/" << y << "=" << Div(x, y) << endl;
        cout << x1 << "/" << y1 << "=" << Div(x1, y1) << endl;
    } catch (int) {  // 异常类型
        cerr << "除数为 0, 计算错误!" << endl;  // 异常处理数据
    } catch (double ) {  // 异常类型
        cerr << "除数为 0.0, 计算错误!" << endl;  // 异常处理数据
    }

    return 0;
}

template <typename T>
T Div(T x, T y) {
    if (y == 0){
        throw y;  // 抛出异常
    }

    return x / y;
}

#include <iostream>

using namespace std;

int triangle(int a, int b, int c);

int main() {
    // 声明变量
    int a, b, c;

    // 赋值
    cout << "Please enter the three side of the triangle:\n";
    cin >> a >> b >> c;

    try {
        // 被检查的语句
        cout << "length of the triangle: " << triangle(a, b, c) << endl;
    } catch (const runtime_error &error) {  // 异常类型
        cerr << error.what() << endl;  // 异常处理数据
    }

    return 0;
}

int triangle(int a, int b, int c) {
    if (a <= 0 || b <= 0 || c <= 0) {
        throw runtime_error("The sides of the triangle cannot be less than or equal to zero");
    } else if (a + b <= c || a + c <= b || b + c <= a) {
        throw runtime_error("The lengths of three sides can't form triangle");
    }
    return a + b + c;
}