Build nested JSON from string of nested keys [duplicate]

Answer 1

// result container
var res = {};

// input data
var inp = [
    'data.location.degree.text=sometexthere',
    'data.otherLocation.degree.otherText=foo',
    'data.location.degree.otherText=bar',
    'we.can.handle.values.that.are_undefined=',
    'we.can.handle.values.that.contain_equals_signs=yes=we=can'
];

// recursive function
var pathToObject = function(resultReference, path)
{
    // split path on dots
    // e.g. data.location.degree.text=sometexthere
    // -> ["data", "location", "degree", "text=sometexthere"]
    var splitPathParts = path.split('.');

    // if there is only one part, we're at the end of our path expression
    // e.g. ["text=sometexthere"]
    if (splitPathParts.length === 1){
        // split "text=sometexthere" into ["text", "sometexthere"]
        var keyAndValue = splitPathParts[0].split('=');

        // set foo = bar on our result object reference
        resultReference[keyAndValue.shift()] = keyAndValue.join('=');
        return;
    }
  
    // the first element of the split array is our current key
    // e.g. for ["data", "location", "degree", "text=sometexthere"],
    // the currentKey would be "data";
    var currentKey = splitPathParts.shift();

    // if our object does not yet contain the current key, set it to an empty object
    resultReference[currentKey] || (resultReference[currentKey] = {});
    
    // recursively call ourselves, passing in
    // the nested scope and the rest of the path.
    // e.g. { data : {} } and 'location.degree.text=sometexthere'
    pathToObject(resultReference[currentKey], splitPathParts.join('.'));
}

for (var i = 0; i < inp.length; i++)
{
    pathToObject(res, inp[i]);
}
console.log(res);

ES6 syntax makes things slightly more terse:

'use strict';

const pathToObject = (resultReference, path) => {
  let [currentKey, ...restOfPath] = path.split('.');
  
  if (restOfPath.length === 0) {
    let [k, ...v] = currentKey.split('=');
    resultReference[k] = v.join('=');
    return;
  }

  resultReference[currentKey] || (resultReference[currentKey] = {});
  pathToObject(resultReference[currentKey], restOfPath.join('.'));
}

let res = {};

[
  'data.location.degree.text=sometexthere',
  'data.otherLocation.degree.otherText=foo',
  'data.location.degree.otherText=bar',
  'we.can.handle.values.that.are_undefined=',
  'we.can.handle.values.that.contain_equals_signs=yes=we=can'
].forEach(x => pathToObject(res, x));

console.log(res);