(PHP 5, PHP 7, PHP 8)
RecursiveIteratorIterator::valid โ Check whether the current position is valid
ๆฌๅฝๆฐ่ฟๆช็ผๅๆๆกฃ๏ผไป ๆๅๆฐๅ่กจใ
ๆญคๅฝๆฐๆฒกๆๅๆฐใ
true if the current position is valid, otherwise false
true
false
