Stuck in while loop even though condition has been met - ruby

Question

I'm writing this script to build a tic-tac-toe game. This is only the beginning (no turns yet). I want to let the user input again if the previous input is invalid.
def display_board(board)
first_row = " #{board[0]} | #{board[1]} | #{board[2]} "
second_row = " #{board[3]} | #{board[4]} | #{board[5]} "
third_row = " #{board[6]} | #{board[7]} | #{board[8]} "
row_divider = "-----------"
puts first_row
puts row_divider
puts second_row
puts row_divider
puts third_row
end
def valid_move?(board,index)
if (index >= 0) && (index <= board.length - 1) && (position_taken?(board,index) != FALSE)
return TRUE
else
return FALSE
end
end
def input_to_index(user_input)
index = user_input.to_i - 1
return index
end
def move(board, index, character = "X")
board[index] = character
end
def position_taken?(board,index)
if (board[index] == "X") || (board[index]=="O")
return FALSE
end
end
def turn(board)
puts "Please enter 1-9:"
user_input = gets.strip
index = input_to_index(user_input)
while valid_move?(board,index) == FALSE
puts "invalid"
turn(board)
end
move(board, index, character = "X")
display_board(board)
end
I am stuck on the while loop. If I input an invalid input and then a valid input, it runs through the while loop instead of ending the program. It should be true. The problem is fixed if I use an if statement instead of a while loop, but I want to learn to use while loops better.

Answer 1

Because you call "turn" (internal) from "turn" (external) and then the internal "turn" called is valid but the board and index on the external
"turn" didn't change.
try this:
def turn(board)
loop do
puts "Please enter 1-9:"
user_input = gets.strip
index = input_to_index(user_input)
if valid_move?(board,index) == TRUE
break
end
puts "invalid"
end
move(board, index, character = "X")
display_board(board)
end