Coding Style – Best Practices for Setting Return Values

coding-style

Whenever you want to return a value from a method, but whatever you return depends on some other value, you typically use branching:

int calculateSomething() {
  if (a == b) {
    return x;
  } else {
    return y;
  }
}

Another way to write this is:

int calculateSomething() {
  if (a == b) {
    return x;
  }
  return y;
}

Is there any reason to avoid one or the other? Both allow adding "else if"-clauses without problems. Both typically generate compiler errors if you add anything at the bottom.

Note: I couldn't find any duplicates, although multiple questions exist about whether the accompanying curly braces should be on their own line. So let's not get into that.

Best Answer

I use both, depending on the method. For example, in a method that decides something, i think that

public boolean isSunday(Calendar cal) {
  if (Calendar.SUNDAY == cal.get(Calendar.DAY_OF_WEEK))
    return true;
  else
    return false;
}

captures the intent of the method better. It is stateless, it is not supposed to be extended, and it is closed in that the if-clause generates all values the method may ever return.

If the method calculates something, or retrieves information, i like the second variant more:

public String getAnswer(int question) {
  if (isAvailable(preciseAnswerService)
    return preciseAnswerService.answer(question);
  return defaultAnswer(question);
}

Here, the fact that one answer is chosen over the other depends on the state of the answerService. We might extend the method later by adding a preciseAnswerCache, or retrieve the answer from somewhere else.

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