arrays - 将字符串添加到嵌套在哈希内部的数组中

Question

我有一组嵌套哈希。我想将字符串“Assembly”添加到与 [:dennis_ritche][:languages] 关联的数组值中

def adding_to_dennis
    programmer_hash =
        {
        :grace_hopper => {
          :known_for => "COBOL",
          :languages => ["COBOL", "FORTRAN"]
        },
        :alan_kay => {
          :known_for => "Object Orientation",
          :languages => ["Smalltalk", "LISP"]
        },
        :dennis_ritchie => {
          :known_for => "Unix",
          :languages => ["C"]
        }
     }
        programmer_hash[:dennis_ritchie][:languages] << "Assembly"
end

这是我没有将 Symbol 隐式转换为 Integer 的错误"

Answer 1

我认为您遇到的问题是您在方法内部操纵散列，结果无意中返回了错误的内容。此方法返回一个数组，因为这是最后执行的操作(<< 在数组上返回修改后的数组)。

要修复它，请定义一个进行操作的方法:

def add_to_hash(hash, programmer = :dennis_ritchie, language = 'Assembly')
  hash[programmer][:languages] << language
end

让它独立于定义:

programmer_hash =
    {
    :grace_hopper => {
      :known_for => "COBOL",
      :languages => ["COBOL", "FORTRAN"]
    },
    :alan_kay => {
      :known_for => "Object Orientation",
      :languages => ["Smalltalk", "LISP"]
    },
    :margaret_hamilton => {
      :known_for => "Apollo Program",
      :languages => ["Assembly"]
    },
    :dennis_ritchie => {
      :known_for => "Unix",
      :languages => ["C"]
    }
 }

然后调用它来操作哈希:

add_to_hash(programmer_hash)

programmer_hash然后更新结构。