Question on a homework assignment

[blumsden]

Having some trouble with a homework assignment, so any help would really be appreciated. I'm not just asking for an answer, trying to learn :)

Problem:
When a function that needs to return something “panics”, return the ‘m_errobj’ member.

It is with an arraylist class. This is what I am given:

template <typename T>
class ArrayList
{ 
private:  
  int m_size;                          // current number of elements
  int m_max;                           // maximum capacity of array m_data
  T* m_data;                           // array to store the elements

  T m_errobj;                          // object to return in case of error 

I made the public function find that returns the index number of x, which does what it should, but I cannot figure out how to handle errors. The assignment creates a arraylist of strings. Which if I understand it correctly(which I may not) m_errobj is a string, so I cannot return a string as an int.

template <typename T>
 int ArrayList<T>::find(const T& x)
{
  for(int k=0;k<m_size;k++)
    if(m_data[k]==x)
      return k;
//  else
//    return -1; or return m_errobj; ?
// not sure how to return my error as m_errobj if x is not found
}

I know it says control reaches end of non-void function because if x is not present it will not have anything to return.

Any pointers in the right direction would be nice.

[AbstractionAnon]

Given the class declaration, find should return an object of type T.
Returning m_errobj in an error situation, m_errobj is also of type T.

So find should look like this:

template <typename T>
T ArrayList<T>::find(const T& x)  // return type of function is T 
{ for(int k=0;k<m_size;k++)
     if (m_data[k]==x)
      return m_data[k];  // return the element (not the index)
   return m_errobj;       // return the error object
}

Not clear how m_errobj is initialized, but I would assume it is passed in through the class constructor (not shown).

[blumsden]

Thanks for the reply. Apparently I don't read directions very well though. It was supposed to return an int of -1 if there was an invalid entry. The whole return m_errobj part is confusing though, it is never initialized anywhere in the assignment so I'm not really sure where he was going with it.

I appreciate the response though, free help is always awesome, thank you.