Programming style: should you return early if a guard condition is not satisfied?

Question

One thing I\'ve sometimes wondered is which is the better style out of the two shown below (if any)? Is it better to return immediately if a guard condition hasn\'t been sat

Answer 1

I prefer the first style, except that I wouldn't create a variable when there is no need for it. I'd do this:

// Style 3
public SomeType aMethod() {

  if (!guardCondition()) {
    return null;
  }

  SomeType result = new SomeType();
  doStuffToResult(result);
  doMoreStuffToResult(result);

  return result;
}