Archives: June 2009

Having one exit point (return) from a function is a good thing. Here is an example of a single exit point:

int MyArray::indexOfElement(int elementToFind){
  int foundIndex = ELEMENT_NOT_FOUND;

  for(int i = 0; i < m_numberOfElements; ++i){
    if(this->elementAtIndex(i) == elementToFind){
      foundIndex = i;
      break;
    }
  }

  return foundIndex;
}

Having multiple exit points can be bad. Here is an example of multiple exit points:

int MyArray::indexOfElement(int elementToFind){
  for(int i = 0; i < m_numberOfElements; ++i){
    if(this->elementAtIndex(i) == elementToFind){
      return i;
    }
  }

  return ELEMENT_NOT_FOUND;
}

The main reason multiple exit points are bad is that they complicate control flow. The more complicated the control flow is, the harder the code is to understand. The harder the code is to understand, the greater the change of introduction bugs whenever the code is modified.