| 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 and strongly-typed solution like the | |
| [`java.time.Duration`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/time/Duration.html) | |
| API. |