47 Switch

A case body breaks automatically, unless it ends with a fallthrough statement.
48 Switch evaluation order

Switch cases evaluate cases from top to bottom, stopping when a case succeeds.
(For example,

```
switch i {
case 0:
case f():
}
```

does not call f if i==0.)
49 Switch with no condition

Switch without a condition is the same as switch true.
This construct can be a clean way to write long if-then-else chains.
50 Advanced Exercise: Complex cube root
50 Advanced Exercise: Complex cube root - implemented