76 lines
1.4 KiB
C++
76 lines
1.4 KiB
C++
|
// throw 的限制
|
||
|
|
// 在使用 throw 抛出异常信息时，受到函数声明处的 throw() 声明的
|
||
|
|
// 可抛出异常类型的限制。
|
||
|
|
|
||
|
|
// 如: 函数内可以抛出任何异常
|
||
|
|
#include <iostream>
|
||
|
|
|
||
|
|
using namespace std;
|
||
|
|
|
||
|
|
class A
|
||
|
|
{
|
||
|
|
public:
|
||
|
|
int n;
|
||
|
|
|
||
|
|
public:
|
||
|
|
A(int n = 0) : n(n) {}
|
||
|
|
};
|
||
|
|
|
||
|
|
// throw() 声明表示不抛出任何异常
|
||
|
|
// throw(int, char, double, A) 表示可以抛出 int, char, double, A 类型的异常
|
||
|
|
void show(int x) throw(int, char, double, A)
|
||
|
|
{
|
||
|
|
switch (x)
|
||
|
|
{
|
||
|
|
case 1:
|
||
|
|
throw 0;
|
||
|
|
break;
|
||
|
|
case 2:
|
||
|
|
throw 'a';
|
||
|
|
break;
|
||
|
|
case 3:
|
||
|
|
throw "abc";
|
||
|
|
break;
|
||
|
|
case 4:
|
||
|
|
throw 1.25;
|
||
|
|
break;
|
||
|
|
case 5:
|
||
|
|
throw A(100); // 抛出自定义类的对象
|
||
|
|
break;
|
||
|
|
// default 可以不写，因为前面已经覆盖了所有情况
|
||
|
|
}
|
||
|
|
cout << "x = " << x << endl;
|
||
|
|
}
|
||
|
|
|
||
|
|
int main()
|
||
|
|
{
|
||
|
|
cout << "输入一个整数: ";
|
||
|
|
int x;
|
||
|
|
cin >> x;
|
||
|
|
try
|
||
|
|
{
|
||
|
|
show(x);
|
||
|
|
}
|
||
|
|
catch (const int &error)
|
||
|
|
{
|
||
|
|
cout << "捕获异常: " << error << endl;
|
||
|
|
}
|
||
|
|
catch (const char &error)
|
||
|
|
{
|
||
|
|
cout << "捕获异常: " << error << endl;
|
||
|
|
}
|
||
|
|
catch (const char *error)
|
||
|
|
{
|
||
|
|
cout << "捕获异常: " << error << endl;
|
||
|
|
}
|
||
|
|
catch (const double &error)
|
||
|
|
{
|
||
|
|
cout << "捕获异常: " << error << endl;
|
||
|
|
}
|
||
|
|
catch (const A &error)
|
||
|
|
{
|
||
|
|
cout << "捕获异常: " << error.n << endl;
|
||
|
|
}
|
||
|
|
return 0;
|
||
|
|
}
|