C++处理异常程序小例子

>>>>所有代码都是在win10+vs2017上运行<<<<

1、处理除数为0

#include "pch.h"
#include<cstdlib>
#include<iostream>
#include<string>
using namespace std;

class Error {
public:
	virtual void showErrorMsg() = 0;
};

class MyExecptionForZero : public Error {
private:
	string errMsg;
public:
	MyExecptionForZero(string str) : errMsg(str) {};
	void showErrorMsg() {
		cout << errMsg << endl;
	}
};

void myTeset(int i, int j) {
	MyExecptionForZero m("除数为0啦");
	cout << "I want to get the result for j/i ..." << endl;
	if (i == 0) { throw m; }
	else { cout << j / i << endl; }
}

int main(int argc, char *argv[]) {
	int i = 0;
	int j = 4;
	try {
		myTeset(i, j);
	}
	catch (Error &e) {
		e.showErrorMsg();
	}
	system("PAUSE");
	return EXIT_SUCCESS;
}

2、访问数组越界

#include "pch.h"
#include<iostream>
using namespace std;
enum index { underflow, overflow };
int array_index(int *a, int n, int index);

class error {
	virtual void showerrormsg() = 0;
};

int main()
{
	int *a = new int[10];
	for (int i = 0; i < 10; i++)
		a[i] = i;

	cout << a[100] << endl;
	try
	{
		cout << a[100] << endl;
		cout << array_index(a, 10, 5) << endl;
		cout << array_index(a, 10, -1) << endl;
		cout << array_index(a, 10, 15) << endl;
	}
	catch (index e)
	{
		if (e == underflow)
		{
			cout << "index underflow!" << endl;
			exit(-1);
		}
		if (e == overflow)
		{
			cout << "index overflow!" << endl;
			exit(-1);
		}
	}
	return 0;
}
int array_index(int *a, int n, int index)
{
	if (index < 0) throw underflow;
	if (index > n - 1) throw overflow;
	return a[index];
}