squashObject.md

Squash Object

Problem

https://www.greatfrontend.com/questions/javascript/squash-object

Problem Description

Implement a function that returns a new object after squashing the input object into a single level of depth where nested keys are "squashed" together with a period delimiter (.).

Example

const object = {
  a: 5,
  b: 6,
  c: {
    f: 9,
    g: {
      m: 17,
      n: 3,
    },
  },
};

squashObject(object); // { a: 5, b: 6, 'c.f': 9, 'c.g.m': 17, 'c.g.n': 3 }

Any keys with null-ish values (null and undefined) are still included in the returned object.

const object = {
  a: { b: null, c: undefined },
};
squashObject(object); // { 'a.b': null, 'a.c': undefined }

It should also work with properties that have arrays as the value:

const object = { a: { b: [1, 2, 3], c: ['foo'] } };
squashObject(object); // { 'a.b.0': 1, 'a.b.1': 2, 'a.b.2': 3, 'a.c.0': 'foo' }

Empty keys should be treated as if that "layer" doesn't exist.

const object = {
  foo: {
    '': { '': 1, 1bar: 2 },
  },
};
squashObject(object); // { foo: 1, 'foo.bar': 2 }

Solution

Squash Object