AppendIterator::valid Checks validity of the current element &reftitle.description; public boolAppendIterator::valid Checks validity of the current element. &reftitle.parameters; &no.function.parameters; &reftitle.returnvalues; Returns &true; if the current iteration is valid, &false; otherwise. &reftitle.seealso; AppendIterator::current AppendIterator::key AppendIterator::next AppendIterator::rewind