其中Array的方法

Question

我几乎试图模仿类的方法where,但在实例上,这个实例是一个哈希数组.例如:这作为一个类方法存在Class.where(:name => "Joe"),所以我希望能够这样做:

@joe = {:name => "Joe", :title => "Mr.", :job => "Accountant"}
@kelly = {:name => "Kelly", :title => "Ms.", :job => "Auditor"}
@people = [@joe, @kelly]

并称之为:

@people.where(:name => 'Joe')

哪个应该返回@joe对象.

我该怎么写呢？

Answer 1

正如我理解的任务,你想要Array#where定义.干得好:

? class Array
?   def where hash
?     return nil unless hash.is_a? Hash # one might throw ArgumentError here
?     self.select do |e| 
?       e.is_a?(Hash) && hash.all? { |k, v| e.key?[k] && e[k] == v }
?     end 
?   end  
? end  
#? :where
? @people.where(:name => 'Joe')
#? [
#  [0] {
#      :job => "Accountant",
#     :name => "Joe",
#    :title => "Mr."
#  }
# ]
? @people.where(:name => 'Joe', :job => 'Accountant')
#? [
#  [0] {
#      :job => "Accountant",
#     :name => "Joe",
#    :title => "Mr."
#  }
# ]
? @people.where(:name => 'Joe', :job => 'NotAccountant')
#? []

希望能帮助到你.

UPD略微更新功能以区nil分值和缺少键.积分给@CarySwoveland.