Question

使用mochijson2解码JSON数据后，我得到了这个结构化的proplist。

 {struct,
 [{<<"query">>,
  {struct,
  [{<<"count">>,4},
   {<<"created">>,<<"2013-11-08T18:33:07Z">>},
   {<<"lang">>,<<"en-US">>},
   {<<"results">>,
    {struct,
        [{<<"quote">>,
          [{struct,
               [{<<"symbol">>,<<"YHOO">>},
                {<<"Ask">>,<<"32.99">>},
                {<<"AverageDailyVolu"...>>,<<"18383000">>},
                {<<"Bid">>,<<"32.98">>},
                {<<"AskRealt"...>>,<<"32.9"...>>},
                {<<"BidR"...>>,<<...>>},
                {<<...>>,...},
                {...}|...]},

如上所示，我想进入[{struct，[{＆lt;＆lt;“符号”＆gt;＆gt;，＆lt;＆lt;“YHOO”＆gt;＆gt;}]] ...等，并开始从那里拉出数据。这是我走了多远，但我似乎无法把它弄出来。任何帮助表示赞赏！

Struct = mochijson2:decode(Body), Struct,
{struct, JsonData} = Struct,
{struct, Symbol} = proplists:get_value(<<"query">>, JsonData),
{struct, New} = proplists:get_value(<<"results">>, Symbol),
{struct, New1} = proplists:get_value(<<"quote">>, New),
 Id = proplists:get_value(<<"symbol">>, New1),
 Id.

Answer 1

表达

{struct, New1} = proplists:get_value(<<"quote">>, New),

包含不正确的匹配。正确地说：

[{struct, New1}] = proplists:get_value(<<"quote">>, New),

Answer 2

为什么选择mochijson2？尝试https://github.com/talentdeficit/jsx这很简单，不会创建原子结构，所以模式匹配更容易（更少的字符），因为一旦创建了proplist。

如何从struct proplist JSON对象中提取正确的信息

2 个答案: