This rule applies whenever an if statement is followed by one or
more else if statements, the final else if shall 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 (x == 0) {
doSomething();
} else if (x == 1) {
doSomethingElse();
}
if (x == 0) {
doSomething();
} else if (x == 1) {
doSomethingElse();
} else {
throw new IllegalStateException();
}