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2010-05-25T14:21:06Z

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==Catch all types of exceptions==

<source lang="cpp">
#include <iostream>
using namespace std;
void XHandler(int test){
try {
if(test==0) throw test;
if(test==1) throw "a";
if(test==2) throw 123.23;
}catch(...){
cout << "Caught one." << endl;
}
}
int main(void){
cout << "Start: " << endl;
XHandler(0);
XHandler(1);
XHandler(2);
cout << "End";
}

</source>

==Catch By Non Const Reference==

<source lang="cpp">
#include <fstream>
#include <iostream>
#include <vector>
#include <string>
#include <exception>
using namespace std;
void readIntegerFile(const string& fileName, vector<int>& dest)
{
ifstream istr;
int temp;
istr.open(fileName.c_str());
if (istr.fail()) {
throw exception();
}
while (istr >> temp) {
dest.push_back(temp);
}
}
int main(int argc, char** argv)
{
vector<int> myInts;
const string fileName = "IntegerFile.txt";
try {
readIntegerFile(fileName, myInts);
} catch (exception& e) {
cerr << "Unable to open file " << fileName << endl;
exit (1);
}
for (size_t i = 0; i < myInts.size(); i++) {
cout << myInts[i] << " ";
}
cout << endl;
return (0);
}

</source>

==Catch By Value==

<source lang="cpp">
#include <fstream>
#include <iostream>
#include <vector>
#include <string>
#include <exception>
using namespace std;
void readIntegerFile(const string& fileName, vector<int>& dest)
{
ifstream istr;
int temp;
istr.open(fileName.c_str());
if (istr.fail()) {
throw exception();
}
while (istr >> temp) {
dest.push_back(temp);
}
}
int main(int argc, char** argv)
{
vector<int> myInts;
const string fileName = "IntegerFile.txt";
try {
readIntegerFile(fileName, myInts);
} catch (exception e) {
cerr << "Unable to open file " << fileName << endl;
exit (1);
}
for (size_t i = 0; i < myInts.size(); i++) {
cout << myInts[i] << " ";
}
cout << endl;
return (0);
}

</source>

==Catch char pointer type exception==

<source lang="cpp">
#include <iostream>
using namespace std;
void XHandler(void)
{
try {
throw "hello";
}
catch(char *) {
cout << "Caught char * inside XHandler." << endl;
throw;
}
}

int main(void)
{
cout << "Start: " << endl;
try {
XHandler();
}
catch(char *)
{
cout << "Caught char * inside main." << endl;
}
cout << "End";

}

</source>

==Catch different types of exception==

<source lang="cpp">
#include <iostream>
using namespace std;
void XHandler(int test) throw(){
if(test==0)
throw test;
if(test==1)
throw "a";
if(test==2)
throw 123.23;
}
int main(void){
cout << "Start: " << endl;
try{
XHandler(0); // try passing 1 and 2 for different responses
}catch(int i){
cout << "Caught an integer." << endl;
}catch(char c){
cout << "Caught a character." << endl;
}catch(double d){
cout << "Caught a double." << endl;
}
cout << "End";
}

</source>

==Catch exception from a function==

<source lang="cpp">
#include <iostream>
using namespace std;
void XHandler(int test) throw(int, char, double){
if(test==0) throw test;
if(test==1) throw "a";
if(test==2) throw 123.23;
}
int main(void){
cout << "Start: " << endl;
try {
XHandler(0); // try passing 1 and 2 for different responses
}
catch(int i) {
cout << "Caught an integer." << endl;
}
catch(char c) {
cout << "Caught a character." << endl;
}
catch(double d) {
cout << "Caught a double." << endl;
}
cout << "End";

}

</source>

==Catch int type exception in a function==

<source lang="cpp">
#include <iostream>
using namespace std;
void XHandler(int test){
try {
if(test) throw test;
}catch(int i){
cout << "Caught exception #: " << i << endl;
}
}
int main(void){
cout << "Start: " << endl;
XHandler(1);
XHandler(2);
XHandler(0);
XHandler(3);
cout << "End";
}

</source>

==Catch more than one type of exceptions==

<source lang="cpp">
#include <iostream>
using namespace std;
void XHandler(int test){
try {
if(test==0) throw test;
if(test==1) throw "a";
if(test==2) throw 123.23;
}catch(int i){
cout << "Caught an integer." << endl;
}catch(...){
cout << "Caught one." << endl;
}
}
int main(void){
cout << "Start: " << endl;
XHandler(0);
XHandler(1);
XHandler(2);
cout << "End";
}

</source>

==Checking for a divide-by-zero exception.==

<source lang="cpp">
#include <iostream>
using std::cout;
using std::cin;
using std::endl;
class DivideByZeroException {
public:
DivideByZeroException()
: message( "attempted to divide by zero" ) { }
const char *what() const { return message; }
private:
const char *message;
};
double quotient( int numerator, int denominator )
{
if ( denominator == 0 )
throw DivideByZeroException();
return static_cast< double > ( numerator ) / denominator;
}
int main()
{
int number1, number2;
double result;
cout << "Enter two integers (end-of-file to end): ";
while ( cin >> number1 >> number2 ) {
try {
result = quotient( number1, number2 );
cout << "The quotient is: " << result << endl;
}
catch ( DivideByZeroException ex ) {
cout << "Exception occurred: " << ex.what() << "\n";
}
cout << "\nEnter two integers (end-of-file to end): ";
}
cout << endl;
return 0;
}

</source>

==Code block of try...catch==

<source lang="cpp">
#include <iostream>
using namespace std;
int main(void){
cout << "Start" << endl;
try {
cout << "Inside try block." << endl;
cout << "Still inside try block." << endl;
}catch(int i){
cout << "Caught an exception--value is: " << endl;
cout << i << endl;
}
cout << "End";
}

</source>

==Finally catch all Exceptions==

<source lang="cpp">
#include <iostream>
#include <stdlib.h>
using namespace std;
void foo()
{
int i, j;
i = 14;
j = 15;
}
void call_foo()
{
int k;
k = 12;
foo();
}
void call_foo2()
{
double x = 1.3;
throw (x);
}
int main()
{
try {
call_foo(); //foo exitted with i and j destroyed
call_foo2();
}
catch (char* message)
{
cerr << message << endl;
exit(1);
}
catch(int n) { cout << "\ncaught it " << n << endl; }
catch( ... )
{
cerr << "THAT"S ALL FOLKS." << endl;
abort();
}
}

</source>

== Localize a try/catch to a function.==

<source lang="cpp">
#include <iostream>
using namespace std;

void myFunction(int test)
{
try{
if( test )
throw test;
}catch(int i) {
cout << "Caught Exception #: " << i << "\n";
}
}
int main()
{
cout << "Start\n";
myFunction(1);
myFunction(2);
myFunction(0);
myFunction(3);
cout << "End";
return 0;
}

</source>

==Use multiple catch statements. ==

<source lang="cpp">

#include <iostream>
using namespace std;

void myFunction(int test)
{
try{
if(test)
throw test; // throw int
else
throw "Value is zero"; // throw char *
}
catch(int i) {
cout << "Caught One! Ex. #: " << i << "\n";
}
catch(char *str) {
cout << "Caught a string: ";
cout << str << "\n";
}
}

int main()
{
cout << "start\n";

myFunction(1);
myFunction(2);
myFunction(0);
myFunction(3);

cout << "end";

return 0;
}

</source>

==Using Multiple catch Statements==

<source lang="cpp">
#include <iostream>
using namespace std;
void myFunction(int test)
{
try{
if(test) throw test;
else throw "Value is zero";
}
catch(int i) {
cout << "Caught Exception #: " << i << "\n";
}
catch(const char *str) {
cout << "Caught a string: ";
cout << str << "\n";
}
}
int main()
{
cout << "Start\n";
myFunction(1);
myFunction(2);
myFunction(0);
myFunction(3);
cout << "End";
return 0;
}

</source>

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