C++中的异常处理（下）
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#include <iostream>
#include <string>
using namespace std;
void Demo()
{
try
{
try
{
throw 'c';
}
catch(int i)
{
cout << "Inner: catch(int i)" << endl;
throw i;
}
catch(...)
{
cout << "Inner: catch(...)" << endl;
throw;
}
}
catch(...)
{
cout << "Outer: catch(...)" << endl;
}
}
/*
假设： 当前的函数式第三方库中的函数，因此，我们无法修改源代码
函数名： void func(int i)
抛出异常的类型： int
-1 ==》 参数异常
-2 ==》 运行异常
-3 ==》 超时异常
*/
void func(int i)
{
if( i < 0 )
{
throw -1;
}
if( i > 100 )
{
throw -2;
}
if( i == 11 )
{
throw -3;
}
cout << "Run func..." << endl;
}
//因为第三方库不太能懂，报的错也看不懂
//所以自己对它封装一下，重解释异常信息
void MyFunc(int i)
{
try
{
func(i);
}
catch(int i)//扔字符串异常
{
switch(i)
{
case -1:
throw "Invalid Parameter";
break;
case -2:
throw "Runtime Exception";
break;
case -3:
throw "Timeout Exception";
break;
}
}
}
int main(int argc, char *argv[])
{
// Demo();
try
{
MyFunc(11);
}
catch(const char* cs)
{
cout << "Exception Info: " << cs << endl;
}
return 0;
}
#include <iostream>
#include <string>
using namespace std;
class Base
{
};
class Exception : public Base
{
int m_id;
string m_desc;
public:
Exception(int id, string desc)
{
m_id = id;
m_desc = desc;
}
int id() const
{
return m_id;
}
string description() const
{
return m_desc;
}
};
/*
假设： 当前的函数式第三方库中的函数，因此，我们无法修改源代码
函数名： void func(int i)
抛出异常的类型： int
-1 ==》 参数异常
-2 ==》 运行异常
-3 ==》 超时异常
*/
void func(int i)
{
if( i < 0 )
{
throw -1;
}
if( i > 100 )
{
throw -2;
}
if( i == 11 )
{
throw -3;
}
cout << "Run func..." << endl;
}
void MyFunc(int i)
{
try
{
func(i);
}
catch(int i)
{
switch(i)
{
case -1:
throw Exception(-1, "Invalid Parameter");
break;
case -2:
throw Exception(-2, "Runtime Exception");
break;
case -3:
throw Exception(-3, "Timeout Exception");
break;
}
}
}
int main(int argc, char *argv[])
{
try
{
MyFunc(11);
}
catch(const Exception& e)//为什么用&：防止拷贝构造，提高效率
{
cout << "Exception Info: " << endl;
cout << " ID: " << e.id() << endl;
cout << " Description: " << e.description() << endl;
}
catch(const Base& e)
{
cout << "catch(const Base& e)" << endl;
}
return 0;
}
如果catch交换顺序：
警告了，但没有报错：（赋值兼容性原则，子类完全可以当作父类来使用，即初始化父类。实际工程中，子类分支放上面，父类下面）
接下来对数组类进行优化：（index可能越界）
const函数专门给const对象调用的，想好工程需不需要这种操作！
//Array.h
#ifndef _ARRAY_H_
#define _ARRAY_H_
#include <stdexcept>
using namespace std;
template
< typename T, int N >
class Array
{
T m_array[N];
public:
int length() const;
bool set(int index, T value);
bool get(int index, T& value);
T& operator[] (int index);
T operator[] (int index) const;
virtual ~Array();
};
template
< typename T, int N >
int Array<T, N>::length() const
{
return N;
}
template
< typename T, int N >
bool Array<T, N>::set(int index, T value)
{
bool ret = (0 <= index) && (index < N);
if( ret )
{
m_array[index] = value;
}
return ret;
}
template
< typename T, int N >
bool Array<T, N>::get(int index, T& value)
{
bool ret = (0 <= index) && (index < N);
if( ret )
{
value = m_array[index];
}
return ret;
}
template
< typename T, int N >
T& Array<T, N>::operator[] (int index)
{
if( (0 <= index) && (index < N) )
{
return m_array[index];
}
else
{
throw out_of_range("T& Array<T, N>::operator[] (int index)");
}
}
template
< typename T, int N >
T Array<T, N>::operator[] (int index) const
{
if( (0 <= index) && (index < N) )
{
return m_array[index];
}
else
{
throw out_of_range("T Array<T, N>::operator[] (int index) const");
}
}
template
< typename T, int N >
Array<T, N>::~Array()
{
}
#endif
//HeapArray.h
#ifndef _HEAPARRAY_H_
#define _HEAPARRAY_H_
#include <stdexcept>
using namespace std;
template
< typename T >
class HeapArray
{
private:
int m_length;
T* m_pointer;
HeapArray(int len);
HeapArray(const HeapArray<T>& obj);
bool construct();
public:
static HeapArray<T>* NewInstance(int length);
int length() const;
bool get(int index, T& value);
bool set(int index ,T value);
T& operator [] (int index);
T operator [] (int index) const;
HeapArray<T>& self();
const HeapArray<T>& self() const;
~HeapArray();
};
template
< typename T >
HeapArray<T>::HeapArray(int len)
{
m_length = len;
}
template
< typename T >
bool HeapArray<T>::construct()
{
m_pointer = new T[m_length];
return m_pointer != NULL;
}
template
< typename T >
HeapArray<T>* HeapArray<T>::NewInstance(int length)
{
HeapArray<T>* ret = new HeapArray<T>(length);
if( !(ret && ret->construct()) )
{
delete ret;
ret = 0;
}
return ret;
}
template
< typename T >
int HeapArray<T>::length() const
{
return m_length;
}
template
< typename T >
bool HeapArray<T>::get(int index, T& value)
{
bool ret = (0 <= index) && (index < length());
if( ret )
{
value = m_pointer[index];
}
return ret;
}
template
< typename T >
bool HeapArray<T>::set(int index, T value)
{
bool ret = (0 <= index) && (index < length());
if( ret )
{
m_pointer[index] = value;
}
return ret;
}
template
< typename T >
T& HeapArray<T>::operator [] (int index)
{
if( (0 <= index) && (index < length()) )
{
return m_pointer[index];
}
else
{
throw out_of_range("T& HeapArray<T>::operator [] (int index)");
}
}
template
< typename T >
T HeapArray<T>::operator [] (int index) const
{
if( (0 <= index) && (index < length()) )
{
return m_pointer[index];
}
else
{
throw out_of_range("T HeapArray<T>::operator [] (int index) const");
}
}
template
< typename T >
HeapArray<T>& HeapArray<T>::self()
{
return *this;
}
template
< typename T >
const HeapArray<T>& HeapArray<T>::self() const
{
return *this;
}
template
< typename T >
HeapArray<T>::~HeapArray()
{
delete[]m_pointer;
}
#endif
//测试程序
#include <iostream>
#include <string>
#include "Array.h"
#include "HeapArray.h"
using namespace std;
void TestArray()
{
Array<int, 5> a;
for(int i=0; i<a.length(); i++)
{
a[i] = i;
}
for(int i=0; i<a.length(); i++)
{
cout << a[i] << endl;
}
}
void TestHeapArray()
{
HeapArray<double>* pa = HeapArray<double>::NewInstance(5);
if( pa != NULL )
{
HeapArray<double>& array = pa->self();
for(int i=0; i<array.length(); i++)
{
array[i] = i;
}
//如果下面这么写for(int i=0; i<10; i++)
//main函数中直接抛异常，可以捕捉到异常Exception
for(int i=0; i<array.length(); i++)
{
cout << array[i] << endl;
}
}
delete pa;
}
int main(int argc, char *argv[])
{
try
{
TestArray();
cout << endl;
TestHeapArray();
}
catch(...)
{
cout << "Exception" << endl以上是关于C++中的异常处理（下）的主要内容，如果未能解决你的问题，请参考以下文章