Try/Catch/Throw in C++

[aemado]

I am really new to the try/catch/throw concept, and can't figure out what is wrong with my code. Any suggestions?

#include <iostream>
 
using namespace std;
 
string msgZero = "Zero denominator\n";
 
void inverse(long value, double& answer) {
 
  if (value > 0) {
 
    answer = 1.0/value;
 
  }
 
  else {
 
    if (value == 0) {
 
        throw msgZero;
 
    }
 
    else {
 
      throw value;
 
    } 
 
  }  
 
  return; }
 
 
 
void fraction (long n, long d, double& result) {
 
   inverse(d, result);
 
   result = n * result; 
 
   return;
 
}     
 
int main () {
 
  while (true) {
 
    long numer, denom;
 
    double ans;
 
    cout << "Enter numerator and 
 
            denominator: ";
 
    if ((cin >> numer >> denom) == 0) break;
 
    try {
 
      fraction(numer, denom, ans);
 
    }
 
    catch (char* str) {
 
      cout << str; }
 
    cout << "Skipped the first catch block"<< endl;
 
    catch (long val) {    
 
      cout << "Negative denominator "<<
 
               val<< endl; }
 
    cout << “*********”<< endl;
 
  }     
 
  return (0);
 
}  
 
 

[gpraghuram]

I am really new to the try/catch/throw concept, and can't figure out what is wrong with my code. Any suggestions?

#include <iostream>
 
using namespace std;
 
string msgZero = "Zero denominator\n";
 
void inverse(long value, double& answer) {
 
  if (value > 0) {
 
    answer = 1.0/value;
 
  }
 
  else {
 
    if (value == 0) {
 
        throw msgZero;
 
    }
 
    else {
 
      throw value;
 
    } 
 
  }  
 
  return; }
 
 
 
void fraction (long n, long d, double& result) {
 
   inverse(d, result);
 
   result = n * result; 
 
   return;
 
}     
 
int main () {
 
  while (true) {
 
    long numer, denom;
 
    double ans;
 
    cout << "Enter numerator and 
 
            denominator: ";
 
    if ((cin >> numer >> denom) == 0) break;
 
    try {
 
      fraction(numer, denom, ans);
 
    }
 
    catch (char* str) {
 
      cout << str; }
 
    cout << "Skipped the first catch block"<< endl;
 
    catch (long val) {    
 
      cout << "Negative denominator "<<
 
               val<< endl; }
 
    cout << “*********”<< endl;
 
  }     
 
  return (0);
 
}  
 
 

Issue 1)You are throwing a string and in the catch block catching char *.
String is equivalent to char*
To find this add catch(...)after the last catch block and you can catch the exception there

Raghuram

[Banfa]

Issue 1)String is equivalent to char*

Is this a typo? I think you mean

String is not equivalent to char *

[gpraghuram]

Is this a typo? I think you mean

String is not equivalent to char *

Yes....Thats a Typo.

Thanks for pointing it.



Raghuram