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Consider a switch statement that doesn't handle all possible values and doesn't
have a default:
```java
enum Colors { RED, GREEN, BLUE }
switch (color) {
case RED:
case GREEN:
paint(color);
break;
}
```
The author's intent isn't clear. There are three possibilities:
1. The default case is known to be impossible. This could be made clear by
adding: \
`default: throw new AssertionError(color);`
2. The code intentionally 'falls out' of the switch on the default case, and
execution continues below. This could be made clear by adding: \
`default: // fall out`
3. The code has a bug, and the missing cases should have been handled.
To avoid this ambiguity, the Google Java Style Guide [requires][style] each
switch statement on an enum type to either handle all values of the enum, or
have a default statement group.
[style]: https://google.github.io/styleguide/javaguide.html#s4.8.4.3-switch-default
|
