The example ignores the fact that pinmode is not just an initialization kind of method that you need to call once, but that there examples where you have to use

The example ignores the fact that pinmode is not just an initialization kind of method that you need to call once, but that there examples where you have to use it in the 'loop'. The most common is the bidirectional serial communication over a single wire, as is used with the DHT22 digital temperature and humidity sensor.