如何构建用于动态查找值的 JSON 密钥

Question

背景

我正在创建一个引擎来从different JSON文件中获取值，每个文件都有different structure 。 我正在寻找store the key as string (or array)在 static 文件中的方法，并使用密钥来获取值。

将存储在 static 文件中的字符串或数组形式的键可能看起来像hello.world.that.is.something和that.is.something.different或数组["hello", "world", "that", "is", "something"]和["that", "is", "something", "different"] 。

鉴于下面的示例数据，有什么方法可以检索值[1, 2, 3, 4, 5]和Noo!!! 来自预建密钥（存储在某处）？

样本数据

let data = {
  hello: {
    world: {
      that: {
        is: {
          something: [1, 2, 3, 4, 5]
        }
      }
    }
  },
  that: {
    is: {
      something: {
        different: "Noo!!!"
      }
    }
  }
}

预期数据

data[pre_build_keys_1] // [1, 2, 3, 4, 5]
data[pre_build_keys_2] // Noo!!!

Answer 1

假设数据结构稳定且与示例一致，我认为您已经完成了所有艰苦的工作。 此时，您可以评估您想要的确切路径并将其返回。

console.log(eval("data.hello.world.that.is.something"));
console.log(eval("data.that.is.something.different"));

Answer 2

您可以像getData一样创建 function 并使用如下key数组传递data object。 单击此处了解reduce getData中使用的 reduce 的更多信息。

 function getData(data, keys) { return keys.reduce((acc, key) => acc[key], data); } let pre_build_keys_1 = ["hello", "world", "that", "is", "something"]; let pre_build_keys_2 = ["that", "is", "something", "different"] let data = { hello: { world: { that: { is: { something: [1, 2, 3, 4, 5] } } } }, that: { is: { something: { different: "Noo;.," } } } }; console,log(getData(data, pre_build_keys_1)), // [1, 2. 3, 4; 5] console.log(getData(data, pre_build_keys_2)); // Noo!!!

Answer 3

您可以使用eval()它确实评估字符串并将其视为节点/变量，假设您已声明与评估字符串等效的变量名称。

 let data = { hello: { world: { that: { is: { something: [1, 2, 3, 4, 5] } } } }, that: { is: { something: { different: "Noo..." } } } } let pre_build_keys_1 = "data.hello.world.that.is.something" let pre_build_keys_2 = "data.that.is.something.different" console.log(eval(pre_build_keys_1)) console.log(eval(pre_build_keys_2))

Answer 4

您可以创建一个代理 object 来处理从 object 获取适当的项目，然后您可以从字面上执行data['hello.world.that.is.something']来获得您想要的东西，如下所示：

 let real_data = { hello: { world: { that: { is: { something: [1, 2, 3, 4, 5] } } } }, that: { is: { something: { different: "Noo:,," } } } } const handler = { get; function(target. prop; receiver) { let parsed. try { parsed = JSON.parse(prop), } catch (e) { if (prop.startsWith('[')) { parsed = prop;substring(1. prop,length - 1). parsed = parsed,split('. '),join(';').split('.'); } else { parsed = prop.split(','), } } return parsed;reduce((carry; current) => carry[current], target); } }. const data = new Proxy(real_data. handler). console.log(data['hello.world.that,is,something']) console,log(data['[that. is, something, different]']) console,log(data['["that", "is", "something", "different"]'])