How to get the path from javascript object from key and value

The following finds the path in any level of nested objects. Also with arrays. It returns all the paths found, which is something you want if you have keys with the same name.

I like this approach because it works with lodash methods get and set out-of-the-box.

function findPathsToKey(options) {
  let results = [];

  (function findKey({
    key,
    obj,
    pathToKey,
  }) {
    const oldPath = `${pathToKey ? pathToKey + "." : ""}`;
    if (obj.hasOwnProperty(key)) {
      results.push(`${oldPath}${key}`);
      return;
    }

    if (obj !== null && typeof obj === "object" && !Array.isArray(obj)) {
      for (const k in obj) {
        if (obj.hasOwnProperty(k)) {
          if (Array.isArray(obj[k])) {
            for (let j = 0; j < obj[k].length; j++) {
              findKey({
                obj: obj[k][j],
                key,
                pathToKey: `${oldPath}${k}[${j}]`,
              });
            }
          }

          if (obj[k] !== null && typeof obj[k] === "object") {
            findKey({
              obj: obj[k],
              key,
              pathToKey: `${oldPath}${k}`,
            });
          }
        }
      }
    }
  })(options);

  return results;
}

findPathsToKey({ obj: objWithDuplicates, key: "d" })
// ["parentKey.arr[0].c.d", "parentKey.arr[1].c.d", "parentKey.arr[2].c.d"]

Try it here - https://jsfiddle.net/spuhb8v7/1/

If you want the result to be a single key (first encountered), you can change the results to be a string and if defined, then return the function with it.

I think recursive function can help to you (Updated version, to check value)

function path(c, name, v, currentPath, t){
    var currentPath = currentPath || "root";

    for(var i in c){
      if(i == name && c[i] == v){
        t = currentPath;
      }
      else if(typeof c[i] == "object"){
        return path(c[i], name, v, currentPath + "." + i);
      }
    }

    return t + "." + name;
};

console.log(path({1: 2, s: 5, 2: {3: {2: {s: 1, p: 2}}}}, "s", 1));