将对象属性数组减少为嵌套对象

如何解决将对象属性数组减少为嵌套对象

我有一个越来越特殊的数组，例如。

const locationProperties = ['earth','americas','canada','saskatchewan'];

我想要一个对象：

{
 earth: {
  americas: {
   canada: {
    saskatchewan: {
      // data 
    }
   }  
  }
 }
}

我想使用 .reduce 创建对象，但在 reducer 中应用转换后，我只剩下 {}

const reducer = (accumulator,item) => {
  accumulator[item] = {};
  return accumulator[item];
}

const reducedArray = locationProperties.reduce(reducer,{});

解决方法

我会推荐一个简单的递归函数，nest -

const nest = ([key,...more],val) =>
  key == null
    ? val
    : {[key]: nest(more,val)}
    
const loc =
  ['earth','americas','canada','saskatchewan']    

console.log(nest(loc,"something"))

{
  "earth": {
    "americas": {
      "canada": {
        "saskatchewan": "something"
      }
    }
  }
}

您也可以使用 reduceRight -

const loc =
  ['earth','saskatchewan']    

const result =
  loc.reduceRight((val,key) => ({[key]: val}),"something")

console.log(result)

{
  "earth": {
    "americas": {
      "canada": {
        "saskatchewan": "something"
      }
    }
  }
}

既然您熟悉 reduce，我将指出 arr.reduceRight(...) 实际上等效于 arr.reverse().reduce(...)。但是在这种情况下使用 reduceRight 效率更高，并且不会改变输入数组 -

const loc =
  ['earth','saskatchewan']    

const result =
  loc.reverse().reduce((val,"something")

console.log(result)

{
  "earth": {
    "americas": {
      "canada": {
        "saskatchewan": "something"
      }
    }
  }
}