将字符串数组转换为JS中的一个对象

Question

Let's say that I have the following array:

[
 {
   path: ["info", "address", "city"]
 },
 {
   path: ["info", "first_name"]
 },
 {
   path: ["info", "last_name"]
 },
 {
   path: ["score"]
 }
]

And I want to convert this to:

{
  personal_info: {
    first_name: some_value,
    last_name: some_value,
    adress: {
     city: some_value
    }
  },
  score: some_value
}

Note: some_value is just another key represented before path key.

I have tried something in this structure:

for(let i = a.length - 1; i >= 0 ; i--){
  if(i == a.length - 1)
    res = { [a[i]] : value};        // assign the value
  else
    res = { [a[i]] : res};          //put the prev object
}

However I don't know how to concatenate from multiple arrays to one object.

Answer 1

You can use either the function reduce or the function forEach to build that desired output.

This approach uses the function reduce , and for the specific values you need to decide how to set them.

 let arr = [ { path: ["info", "address", "city"] }, { path: ["info", "first_name"] }, { path: ["info", "last_name"] }, { path: ["score"] }], value = 'some_value', personalInfoKey = 'personal_info', result = arr.reduce((a, {path}) => { let [type, ...keys] = path; if (type === 'info') { if (keys.length === 1) a[personalInfoKey][keys.pop()] = value; else { a[personalInfoKey] = a[personalInfoKey] || {}; let current = a[personalInfoKey]; keys.forEach((k, i, ar) => current = current[k] = i === ar.length - 1 ? value : {}); } } else a[type] = value; return a; }, {}); console.log(result); 

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Answer 2

You can use 2 reduce s. The first one is to loop thru the array. The second one is to construct the result object.

 var arr = [ {"path":["info","address","city"],"value":1}, {"path":["info","first_name"],"value":2}, {"path":["info","last_name"],"value":3}, {"path":["score"],"value":4} ] var result = arr.reduce((c, v) => { var t = v.path.reduce((a, o, i) => { o = o === "info" ? "personal_info" : o; if (i < v.path.length - 1 && !a[o]) a[o] = {}; if (i < v.path.length - 1) return a[o]; else return a; }, c); t[v.path[v.path.length - 1]] = v.value; return c; }, {}); console.log(result); 

Answer 3

You could iterate the array and reduce the keys with default object for assigning the vlaue.

 function setValue(object, path, value) { var last = path.pop(); path.reduce((o, k) => o[k] = o[k] || {}, object)[last] = value; return object; } var data = [{ value: "Düsseldorf", path: ["info", "address", "city"] }, { value: "Jane", path: ["info", "first_name"] }, { value: "Smith", path: ["info", "last_name"] }, { value: 11000, path: ["score"] }], object = data.reduce((o, { path, value }) => setValue(o, [...path], value), {}); console.log(object); 

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Answer 4

 const data = [ { path: ["info", "address", "city"] }, { path: ["info", "first_name"] }, { path: ["info", "last_name"] }, { path: ["score"] } ]; const newObject = {}; function setValueByKeypath(currentObject, path, value) { for (let i = 0, len = path.length; i < len; i++) { const key = path[i]; // if it is the last path part, add the value else we have to got on building objects const keyValue = (i === len - 1) ? value : {}; // test if there is already a given key and if not create one or if it is the last part of the key add the value if (typeof currentObject[key] === "undefined") { currentObject[key] = keyValue; } currentObject = currentObject[key]; } } for (let i = 0, len = data.length; i < len; i++ ) { // build the nested path in the object by the given array data[i].path setValueByKeypath(newObject, data[i].path, "someValue"); } console.log(newObject); // create a reference 'personal_info' to 'info' newObject.personal_info = newObject.info; // delete the 'info' key delete newObject.info; console.log(newObject); 

First go through those paths. And secondly turn the info key into a personal_info key.