if – else coding style best practices

lukaseder

14 years ago

The following post is going to be an advanced curly-braces discussion with no right or wrong answer, just more “matter of taste”. It is about whether to put “else” (and other keywords, such as “catch”, “finally”) on a new line or not. Some may write


if (something) {
  doIt();
} else {
  dontDoIt();
}

I, however, prefer


if (something) {
  doIt();
} 
else {
  dontDoIt();
}

That looks silly, maybe. But what about comments? Where do they go? This somehow looks wrong to me:


// This is the case when something happens and blah
// blah blah, and then, etc...
if (something) {
  doIt();
} else {
  // This happens only 10% of the time, and then you
  // better think twice about not doing it
  dontDoIt();
}

Isn’t the following much better?


// This is the case when something happens and blah
// blah blah, and then, etc...
if (something) {
  doIt();
}

// This happens only 10% of the time, and then you
// better think twice about not doing it
else {
  dontDoIt();
}

In the second case, I’m really documenting the “if” and the “else” case separately. I’m not documenting the call to “dontDoIt()”. This can go further:


// This is the case when something happens and blah
// blah blah, and then, etc...
if (something) {
  doIt();
}

// Just in case
else if (somethingElse) {
  doSomethingElse();
}

// This happens only 10% of the time, and then you
// better think twice about not doing it
else {
  dontDoIt();
}

Or with try-catch-finally:


// Let's try doing some business
try {
  doIt();
}

// IOExceptions don't really occur
catch (IOException ignore) {}

// SQLExceptions need to be propagated
catch (SQLException e) {
  throw new RuntimeException(e);
}

// Clean up some resources
finally {
  cleanup();
}

It looks tidy, doesn’t it? As opposed to this:


// Let's try doing some business
try {
  doIt();
} catch (IOException ignore) {
  // IOExceptions don't really occur
} catch (SQLException e) {
  // SQLExceptions need to be propagated
  throw new RuntimeException(e);
} finally {
  // Clean up some resources
  cleanup();
}

I’m curious to hear your thoughts…