| Compile-time constant expressions that overflow are a potential source of bugs. |
| |
| Literals without an explicit `L` suffix have type `int`, so the following |
| multiplication expression is evaluated as an integer before being widened to |
| `long`. The value is greater than `Integer.MAX_VALUE`, so it wraps around to |
| `-1857093632`. |
| |
| ```java |
| static final long NANOS_PER_DAY = 24 * 60 * 60 * 1000 * 1000 * 1000; |
| ``` |
| |
| The intent was probably for the multiplication expression to be evaluated as a |
| `long` instead of an `int`. |
| |
| ```java |
| static final long NANOS_PER_DAY = 24L * 60 * 60 * 1000 * 1000 * 1000; |
| ``` |
| |
| If you find yourself doing this kind of time based math, consider using an API |
| that provides a safer, more readable solution. For example, on the sub-second |
| scale, see [`TimeUnit.convert`]. |
| |
| [`TimeUnit.convert`]: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/TimeUnit.html#convert(long,%20java.util.concurrent.TimeUnit) |
