flat-obj

flat-obj

A tiny (188B) utility to flatten an object with customizable glue

This module squashes a nested object (including its internal Arrays) so that the output is a flat object – AKA, it has a single level of depth. By default, the _ character is used to glue/join layers' keys together. This is customizable, of course.

Finally, any keys with nullish values (null and undefined) are not included in the return object.

Install

$ npm install --save flat-obj

Usage

import flatObj from 'flat-obj';

flatObj({
  a: 'hi',
  b: {
    a: null,
    b: ['foo', '', null, 'bar'],
    d: 'hello',
    e: {
      a: 'yo',
      b: undefined,
      c: 'sup',
      d: 0,
      f: [
        { foo: 123, bar: 123 },
        { foo: 465, bar: 456 },
      ]
    }
  },
  c: 'world'
});
// {
//   a: 'hi',
//   b_b_0: 'foo',
//   b_b_1: '',
//   b_b_3: 'bar',
//   b_d: 'hello',
//   b_e_a: 'yo',
//   b_e_c: 'sup',
//   b_e_d: 0,
//   b_e_f_0_foo: 123,
//   b_e_f_0_bar: 123,
//   b_e_f_1_foo: 465,
//   b_e_f_1_bar: 456,
//   c: 'world'
// }

Note: null and undefined values are purged.

API

flatObj(input, [glue])

Returns: Object

Returns a new object with a single level of depth.

Important: An object is always returned despite input type.

input

Type: Object|Array

The object to flatten.

glue

Type: String
Default: _

A string used to join parent key names to nested child key names.

const foo = { bar: 123 };

flatObj({ foo }); //=> { foo_bar: 123 }
flatObj({ foo }, '.'); //=> { 'foo.bar': 123 }

Benchmarks

Running on Node.js v10.13.0

Validation:
  ✔ flat
  ✔ flatten-object
  ✔ flat-obj@1.x
  ✔ flat-obj

Benchmark:
  flat               x 186,002 ops/sec ±1.28% (89 runs sampled)
  flatten-object     x 188,715 ops/sec ±0.22% (94 runs sampled)
  flat-obj@1.x       x 274,414 ops/sec ±1.03% (95 runs sampled)
  flat-obj           x 363,332 ops/sec ±0.57% (97 runs sampled)

License

MIT © Luke Edwards