This rule applies whenever an if statement is followed by one or more else if statements; the final else if
should be followed by an else statement.
The requirement for a final else statement is defensive programming.
The else statement should either take appropriate action or contain a suitable comment as to why no action is taken. This is
consistent with the requirement to have a final default clause in a switch statement.
if (condition1) {
do_something();
} else if (condition2) {
do_something_else();
}
if (condition1) {
do_something();
} else if (condition2) {
do_something_else();
} else {
throw new InvalidArgumentException('message');
}