explain code

Code:

// Ex6_04.cpp  Using exception handling
#include <iostream>
using std::cout;
using std::endl;

int main(void)
{
  int counts[] = {34, 54, 0, 27, 0, 10, 0};
  int time = 60;                       // One hour in minutes

  for(int i = 0 ; i < sizeof counts/sizeof counts[0] ; i++)
    try
    {
      cout << endl
           << "Hour " << i+1;

      if(counts[i] == 0)
        throw "Zero count - calculation not possible.";

      cout << " minutes per item: "
           << static_cast<double>(time)/counts[i];
    }
    catch(const char aMessage[])
    {
      cout << endl
           << aMessage
           << endl;
    }
  return 0;
}

Can any one explain the above code

I cannot understand the catch part
Is catch a function? from where the const char aMessage[] came from? what does it containt.

You might want to read up on exceptions.

catch is the receiving part of a throw [both catch and throw are C++ keywords] - that is part of exception handling. You probably need to re-read the chapter of the book that deals with exception handling if you don't understand how that works [it's both simple (as a concept) and complex (as in there are many different things you can do, that does things a bit differently)].

--
Mats

my book doesn't explains that part,

I might search in google

thx anyways

Originally Posted by manzoor

my book doesn't explains that part,

I might search in google

thx anyways

So where does the exercise come from, if it's not part of your book?

--
Mats

*sigh*

A perfect example of how not to use exception coupled with a bad catch and obtuse source structure. ;_;

Soma

I'm saying that my book doesn't explains the catch part of the code, it explains everything else

the code is from the book btw

So may I know that how the catch can have arguments ?

Code:

catch (type_of_exception var_name) {
    access and use var_name
}

I agree with phantomotap that it is a rather bad example of using exceptions, though. Exceptions are more like smart error codes for cases where you don't know what do about an error condition within the function (other than that you can't continue and the calling function - or the functions above that - should do something). In this example you do: print a message and carry on with the next item, so you might just print the message where you throw it instead.

Looks like it's from Beginning Visual C++ 2005, from the chapter on Program Structure, which includes a section on...

wait for it...

Exceptions!