使用參數ruby作爲哈希鍵

Question

我想創建一個代碼來命名有機化學化合物。我如何使用參數（num，bond）作爲哈希鍵？忽略我對全局變量做了什麼，只是想了解我的意圖。

class Molecule 
def molecule_name(num, bond) 
    @num = { 1 => 'met', 2 => 'et', 3=> 'prop', 4 => 'but'} 
    @bond = {1 => 'ano', 2 => 'eno', 3 => 'ino'} 
end 
a = Molecule.new; a = a.molecule_name(2,1) 
print a 
end 

Answer 1

的問題是有點不清楚，但我想這大概是你想達到什麼目的：

class Molecule 
    def initialize(num, bond) 
    @num = num 
    @bond = bond 
    end 

    NAMES = {1 => 'met', 2 => 'et', 3 => 'prop', 4 => 'but'} 
    BONDS = {1 => 'ano', 2 => 'eno', 3 => 'ino'} 

    def molecule_name 
    [ NAMES[@num], BONDS[@bond] ] 
    end 
end 

a = Molecule.new(2, 1) 
a.molecule_name # => ["et", "ano"] 

Answer 2

我試圖修改儘可能少的情況下仍能工作示例：

class Molecule 
    attr_reader :num, :bond 
    def to_s 
    "#{@num}, #{@bond}" 
    end 

    def molecule_name(num, bond) 
    @num = { 1 => 'met', 2 => 'et', 3=> 'prop', 4 => 'but'}[num] 
    @bond = {1 => 'ano', 2 => 'eno', 3 => 'ino'}[bond] 
    end 
end 

a = Molecule.new 
a.molecule_name(2,1) 
puts a 
#=> et, ano 
puts a.num 
#=>et 
puts a.bond 
#=>ano 

這個例子將是一個有點更紅寶石肥胖型：

class Molecule 
    attr_reader :num, :bond 
    @@nums = { 1 => 'met', 2 => 'et', 3=> 'prop', 4 => 'but'} 
    @@bonds = {1 => 'ano', 2 => 'eno', 3 => 'ino'} 

    def initialize(num_id, bond_id) 
    @num = @@nums[num_id] 
    @bond = @@bonds[bond_id] 
    end 

    def name 
    "#{num}, #{bond}" 
    end 
end 

a = Molecule.new(2,1) 
puts a.name