Code should Express Intent and NOT Rely on Side-effects
Consider the following code
1 2 3 4 5 6 7 8 9 10 | public static <T> String join(Iterator<T> itr, String seperator) { StringBuilder sb = new StringBuilder(); while (itr.hasNext()) { if (sb.length() != 0) { sb.append(separator); } sb.append(itr.next().toString()); } return sb.toString(); } |
When I read through this code, checking StringBuffer’s length and then appending a separator does not communicate the intent very well.
4 5 6 | if (sb.length() != 0) { sb.append(separator); } |
Here we are relying on the side-effect (StringBuffer’s length) instead of asking the iterator. So the code does not flow smoothly. Also, now if you want to add a prefix to the joined String this logic might break.
IMHO, following code solves this problem.
1 2 3 4 5 6 7 8 9 10 | public static <T> String join(Iterator<T> itr, String seperator) { StringBuilder sb = new StringBuilder(); while (itr.hasNext()) { sb.append(itr.next().toString()); if(itr.hasNext()) { sb.append(separator); } } return sb.toString(); } |
