计算相同索引

Question

我有一系列符号：

main_row = [:b, :r, :g, :o] 

和另一个数组cells，其中填充了Cell class：

的实例

class Cell
  attr_accessor :colour
  def initialize(colour = nil)
    @colour = colour
  end
end

cells = [Cell.new(:b), Cell.new(:g), Cell.new(:r), Cell.new(:o)]

我需要计算cells中main_row中的元素与correct中具有相同索引的元素具有相同颜色的数量，并将它们存储在名为correct # => 2 的变量中。

Date

Answer 1

Cell = Struct.new(:colour)
cells = [Cell.new(:b), Cell.new(:g), Cell.new(:r), Cell.new(:o)]
main_row = [:b, :r, :g, :o] 

correct = cells.zip(main_row).count { |cell, colour| cell.colour == colour }
#=> 2

Answer 2

Cell = Struct.new(:colour)
cells = [Cell.new(:b), Cell.new(:g), Cell.new(:r), Cell.new(:o)]
main_row = [:b, :r, :g, :o].each

cells.count{|c| c.colour == main_row.next } # => 2

Answer 3

main_row.each_index.count { |i| main_row[i] == cells[i].colour }
  #=> 2

Answer 4

cells = [Cell.new(:b), Cell.new(:g), Cell.new(:r), Cell.new(:o)]
main_row = [:b, :r, :g, :o] 
cells.select.with_index { |c, i| i == main_row.index(c.colour) }.size
#=>2

Answer 5

cells = [Cell.new(:b), Cell.new(:g), Cell.new(:r), Cell.new(:o)]
main_row = [:b, :r, :g, :o]    
cells.map.with_index{ |c, i| i == main_row.index(c.colour) }.count(true)
#=> 2