Refactoring Examples

Examples from Martin Fowler's Book:

Refactoring Improving the design of Existing Code,

Addison Wesley, 2001, ISBN 0201485672

Example 1: Which code is easier to understand? Why?

double getPayAmount() {
  double result;
  if (_isDead)

     result = deadAmount();
  else {
    if (_isSeparated)

      result = separatedAmount();
    else {
      if (_isRetired)

         result = retiredAmount();
      else

         result = normalPayAmount();
    }
  }
  return result;
}

double getPayAmount() {
  if (_isDead) 
    return deadAmount();
  if (_isSeparated) 
    return separatedAmount();
  if (_isRetired) 
    return retiredAmount();

  return normalPayAmount();
}

1_Answer

Example 1: Which code is easier to understand? Why?

 if (!isSummer(date))
  charge = winterCharge(quantity);
 else
  charge = summerCharge(quantity);

 if (isSummer(date))
  charge = summerCharge(quantity);
 else
  charge = winterCharge(quantity);

2_Answer