2012-11-16 62 views

回答

5

另一种方法,使用发现

1.9.3p194 :007 > array1 = [{"name"=>"Bob"}, {"age"=>"30"}] 
=> [{"name"=>"Bob"}, {"age"=>"30"}] 
1.9.3p194 :008 > hash1 = array1.find { |h| h['age'] == "30" } 
=> {"age"=>"30"} 
1.9.3p194 :009 > hash1['age'] = 31 
=> 31 
1.9.3p194 :010 > array1 
=> [{"name"=>"Bob"}, {"age"=>31}] 
2

既然你真的有是哈希的数组,你可以索引数组,以获得第二哈希值,然后通过传递"age"作为关键更新值:

1.9.3p194 :001 > h = [{"name"=>"Bob"}, {"age"=>"30"}] 
=> [{"name"=>"Bob"}, {"age"=>"30"}] 
1.9.3p194 :002 > h[1]["age"] = 31 
=> 31 
1.9.3p194 :003 > h 
=> [{"name"=>"Bob"}, {"age"=>31}] 
1

这样做:

[{"name"=>"Bob"}, {"age"=>"30"}][1]["age"] = 31 
3

为什么不将数组转换成更简单,更灵活的数组?你的阵列是哭出来的是一个值对象:

class Person 
    attr_accessor :name, :age 
    def initialize arr 
    arr.each { |h| h.each { |k,v| instance_variable_set("@#{k}", v) } } 
    end 
    def to_hash_array 
    instance_variables.each_with_object([]) do |iv, arr| 
     arr << {iv.to_s.sub('@','') => instance_variable_get(iv)} 
    end 
    end 
end 

def hash_array_to_person arr 
    person = Person.new 
    arr.each { |h| h.each { |k,v| person.send("#{k}=", v) } } 
    person 
end 

example = [{"name"=>"Bob"}, {"age"=>"30"}] 
bob = Person.new(example) 

p bob 
p bob.to_hash_array 
bob.age = 31 
p bob.to_hash_array 

输出:

#<Person:0x00000000fe8418 @name="Bob", @age="30"> 
[{"name"=>"Bob"}, {"age"=>"30"}] 
[{"name"=>"Bob"}, {"age"=>31}] 

Ruby是不是C,你有这么比基本的原始数据类型,更提供给您。