ruby-on-rails - 如何修复错误 "void value expression"？

Question

我写了一个井字游戏程序。我遇到问题的程序部分是出现错误:

tac.rb:63: void value expression
tac.rb:65: void value expression

此错误来 self 的 check_win 方法。

if str == "xxx"
                                return true  and puts "X Wins!"
                        str == "ooo"
                                return true and puts "O Wins!"

在我添加“X wins”和“O wins”语句后，它给了我这个错误。

这是我的整个程序:

class Game

        def initialize
                @board=Array.new
                @board[1]="1  __|"
                @board[2]="__"
                @board[3]="|__"
                @board[4]="\n2  __|"
                @board[5]="__"
                @board[6]="|__"
                @board[7]="\n3    |"
                @board[8]="  "
                @board[9]="|  "
                @turn="x"
                @win_status = false
        end

        def turn
                @turn
        end

        def show_board
                puts "  1   2   3"
                @board.each do |i|
                        print i
                end
                puts ""
        end

        def set_turn #switches turns
        if @turn == "x"
                @turn = "o"
        else @turn == "o"
                @turn = "x"
        end
        end

        def make_move
                puts "Enter x coordinate"
                x=gets.to_i
                puts "Enter y coordinate"
                y=gets.to_i
@board[1]="1  _"+@turn+"|"   if y==1 && x==1
@board[2]="_"+@turn    if y==2 && x==1
@board[3]="|_"+@turn   if y==3 && x==1
@board[4]="\n2  _"+@turn+"|" if y==1 && x==2
@board[5]="_"+@turn    if y==2 && x==2
@board[6]="|_"+@turn   if y==3 && x==2
@board[7]="\n3   "+@turn+"|" if y==1 && x==3
@board[8]=" "+@turn    if y==2 && x==3
@board[9]="|"+@turn+" \n"    if y==3 && x==3
        end
 def win_combo
                return [[@board[1][1] + @board[2][1] + @board[3][2]], [@board[4][2] + @board[5][1] + @board[6][2]], [@board[7][1] + @board[8][1] + @board[9][1]],[@board[1][1] + @board[4][2] + @board[7][1]], [@board[2][1] + @board[5][1] + @board[8][1]], [@board[3][2] + @board[6][2] + @board[9][1]], [@board[1][1] + @board[5][1] + @board[9][1]], [@board[3][2] + @board[5][1] + @board[7][1]]]
        end

        def check_win
                #if some row or column or diagonal is "xxx" or "ooo" then set @win_status = true
                self.win_combo.each do |arr|
                        str = arr.join
                        if str == "xxx"
                                return true  and puts "X Wins!"
                        str == "ooo"
                                return true and puts "O Wins!"

                        end
                end
                return false
        end
end


g = Game.new
while g.check_win != true
        g.show_board
        g.set_turn
        g.make_move
end

Answer 1

您需要一个 elsif 来让 ruby​​ 知道条件发生变化的位置。这是正确的代码:

if str == "xxx"
  puts "X Wins!"
  return true 
elsif str == "ooo"
  puts "O Wins!"
  return true
end

您还需要结束您的 if block 。