Reverse Conditional (by Bill Murphy and Martin Fowler) <IMG SRC = "http://www.refactoring.com/catalog/new.gif" border=0>

Reverse Conditional

Refactoring contributed by Bill Murphy and Martin Fowler

You have a conditional that would be easier to understand if you reversed its sense.

Reverse the sense of the conditional and reorder the conditional's clauses.


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


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

Motivation

Often conditionals can be phrased in way that makes them hard to read. This is particularly the case when they have a not in front of them. If the conditional only has a "then" clause and no "else" clause, this is reasonable. However if the conditional has both clauses, then you might as well reverse the conditional.

Mechanics

• Remove negative from conditional.


• Switch clauses


• Compile and test.

There's further discussion on this kind of refactoring on the wiki.




***** 아름다운프로님에 의해서 게시물 복사 + 카테고리변경되었습니다 (2003-12-18 17:27)