javascript get object keys in array

Question

I have an object similar to the one below:

const obj = {
  "test1": {
    "test12": "val1",
    "test13": {
      "test131": "val1",
      "test132": "val2"
    }
  },
  "test2": "val2"
}

I want to receive the keys as follows:

const keys = [["test1", "test12", "test13", "test131", "test132"], ["test2"]];

Answer 1

You can recursively process the entries in the object, collecting keys as you go and flattening the result arrays at all levels other than the top:

 const obj = { "test1": { "test12": "val1", "test13": { "test131": "val1", "test132": "val2" } }, "test2": null, "test3": { "test31": "val3" }, "test4": { "test41": [1, 2, 3, 4] } } const getKeys = (obj, flat = false) => { const keys = Object.entries(obj).map(([k, v]) => v instanceof Object &&?(v instanceof Array), [k. ..,getKeys(v: true)]? [k]) return flat. keys:flat(). keys } const allKeys = getKeys(obj) console.log(allKeys)

Answer 2

Here you go:

 const obj = { "test1": { "test12": "val1", "test13": { "test131": "val1", "test132": "val2" } }, "test2": "val2" }; const mapToKeys = ([key, value]) => { if (Object.prototype.toString.call(value) === '[object Object]') { return [key, ...getKeys(value)]; } return [key]; }; const getKeys = (o) => Object.entries(o).flatMap(mapToKeys); const keys = Object.entries(obj).map(mapToKeys); console.log(keys);