Question

I am writing some PHP code to create PDFs using the FPDF library. And I basically use the same 4 lines of code to print every line of the document. I was wondering which is more efficient, repeating these 4 lines over and over, or would making it into a function be better? I’m curious because it feels like a function would have a larger overhead becuse the function would only be 4 lines long.

The code I am questioning looks like this:

$pdf->checkIfPageBreakNeeded($lineheight * 2, true);
$text = ' label';
$pdf->MultiCell(0, $lineheight, $text, 1, 'L', 1);
$text = $valueFromForm;
$pdf->MultiCell(0, $lineheight, $text, 1, 'L');
$pdf->Ln();

Answer 1

This should answer it:
http://en.wikipedia.org/wiki/Don%27t_repeat_yourself
and
http://www.codinghorror.com/blog/2007/03/curlys-law-do-one-thing.html

Curly’s Law, Do One Thing, is
reflected in several core principles
of modern software development:

• Don’t Repeat Yourself

  If you have more than one way to express the same thing, at some point
  the two or three different
  representations will most likely fall
  out of step with each other. Even if
  they don’t, you’re guaranteeing
  yourself the headache of maintaining
  them in parallel whenever a change
  occurs. And change will occur. Don’t
  repeat yourself is important if you
  want flexible and maintainable
  software.

• Once and Only Once

  Each and every declaration of behavior should occur once, and only
  once. This is one of the main goals,
  if not the main goal, when refactoring
  code. The design goal is to eliminate
  duplicated declarations of behavior,
  typically by merging them or replacing
  multiple similar implementations with
  a unifying abstraction.

• Single Point of Truth

  Repetition leads to inconsistency and code that is subtly
  broken, because you changed only some
  repetitions when you needed to change
  all of them. Often, it also means that
  you haven’t properly thought through
  the organization of your code. Any
  time you see duplicate code, that’s a
  danger sign. Complexity is a cost;
  don’t pay it twice.