Question

我的哈希值都是空白的。

hash_obj = {：username =＆gt; ＆＃39;＆＃39;，：name =＆gt; ＆＃39;＆＃39;，：phone =＆gt; ＆＃39;＆＃39;}

get_row_datas正在获取数据，这是一个数组。

[[john1，john2,0123]，[john3，john4,345]]

我试图将这些值分配到hash_obj中，以便它变为

hash_array = {：username =＆gt; ＆＃39; john1＆＃39;，：name =＆gt; ＆＃39; john2＆＃39;，：phone =＆gt; ＆＃39; 0123＆＃39;}，{：username =＆gt; ＆＃39; john3＆＃39;，：name =＆gt; ＆＃39; john4＆＃39;，：phone =＆gt; ＆＃39; 345＆＃39;}

def get_hash_array
  first_row_data = get_first_row
  hash_obj = Hash.new
  first_row_data.each do |column|
    hash_obj[column.to_sym] = ''
  end

  hash_array = Hash.new

  row_datas = get_row_datas
  row_datas.each_with_index do |row, row_count|
    puts "Rows datas #{row} and row count is #{row_count}"
    hash_obj.each_with_index do |attribute, attribute_count|
      hash_obj[attribute] = row[attribute_count] //problem occurs
      puts "This is attribute #{attribute} and count #{attribute_count}"
      puts "#{row[attribute_count]}"
    end
  end

  hash_obj
end

我想问一下如何赋值，因为你可以看到我的代码，会出现错误。 RuntimeError：在迭代期间无法将新密钥添加到哈希

Answer 1

您也可以尝试以下技术：

hash_obj = {:username => '', :name => '', :phone => ''}
val = [[:john1, :john2, 0123], [:john3,:john4, 345]]

val.map{|i| Hash[hash_obj.keys.zip(i)]}
# => [{:username=>:john1, :name=>:john2, :phone=>83},
#     {:username=>:john3, :name=>:john4, :phone=>345}]

但我用地图做到了！但不是地图，你知道是什么原因吗？

原因如下：

map {| item | block}→new_ary ：创建一个包含块返回值的新数组。

hash_obj = {:username => '', :name => '', :phone => ''}
val = [[:john1, :john2, 0123], [:john3,:john4, 345]]
new_hash = val.map{|i| Hash[hash_obj.keys.zip(i)]}
val
# => [[:john1, :john2, 83], [:john3, :john4, 345]]

<强>图！ {|项目| block}→ary ：为self的每个元素调用给定的块一次，用块返回的值替换元素

hash_obj = {:username => '', :name => '', :phone => ''}
val = [[:john1, :john2, 0123], [:john3,:john4, 345]]
new_hash = val.map!{|i| Hash[hash_obj.keys.zip(i)]}
val
# => [{:username=>:john1, :name=>:john2, :phone=>83},
#     {:username=>:john3, :name=>:john4, :phone=>345}]

通过迭代ruby分配哈希值

1 个答案: