Void would be encountered as a return type
public void off() << Look! There! { if (are you sure box) application.terminate; //PSEUDO CODE ALERT!! ?? }
Sometimes, a boolean return type would be better, performing checks on the data passed and returning false if the data didn't verify. In the example, there is unlikely to be a need to return something. There doesn't need to be any data passed, either. For example, an object representing a bank account may have a close() method. It might refuse to close the account, and return false if there is still an overdraft.