We’ve recently revisted our Java Coding Conventions. For several years we are now using a style based on the excellent book The Elements of Java Style by RougeWave. It follows the Sun Code Style in many aspects and adds a lot of reasoning.
Our Code Style differs mainly in two aspects:
- We place curly braces on new lines
- We use a maximum line length of 130 characters
I am well aware that there are religious opinions regarding those questions but after reconsidering our style we came to the conclusion that both differences actually make sense.
Lining up curly braces vertically (called Allman or ANSI style) makes it easy to check that the braces match. The indented code is clearly set apart from the containing statement by lines that are almost completely whitespace which makes the code easier to read. In contrast to K&R style it consumes more space but today’s screens are well capable to show more than the ancient 24 lines.
Good:
if (condition)
{
body;
}
Bad:
if (condition) {
body;
}
The reason to limit the line length to 80 characters comes from the limitation of old printers that usually printed 80 characters per line. We seldomly print code on paper and modern printers are well capable to print at other resolutions. Limiting us to to 80 characters would waste a lot of screen space as with a decent screen size showing 130 characters still leaves enough place for the IDE to show up additional frames including outlines and project files left and right to the code.
What we learned: Use the mainstream conventions by default. Challenge them and check if the underlying assumptions hold true in your environment. Only derive if there is enough benefit to justify the change.