toDefaulted (Lodash Compatibility)

::: warning Use spread operator or Object.assign instead

This toDefaulted function operates slowly due to deep cloning and complex default value handling.

Use faster and more modern spread operator (...) or Object.assign() instead.

:::

Creates a new object by applying default values to an object.

typescript

const defaulted = toDefaulted(object, ...sources);

Usage

`toDefaulted(object, ...sources)`

Use toDefaulted when you want to create a new object by applying default values from one or more source objects to a target object. Default values are only set for properties that are undefined or come from Object.prototype.

typescript

import { toDefaulted } from 'es-toolkit/compat';

// Basic default value assignment
const user = { name: 'John' };
const defaults = { name: 'Anonymous', age: 25, role: 'user' };
toDefaulted(user, defaults);
// => { name: 'John', age: 25, role: 'user' }

// Apply defaults from multiple sources
const config = { theme: 'dark' };
const defaults1 = { theme: 'light', lang: 'en' };
const defaults2 = { lang: 'ko', region: 'Asia' };
toDefaulted(config, defaults1, defaults2);
// => { theme: 'dark', lang: 'en', region: 'Asia' }

Only undefined values are replaced with defaults, while null values are preserved.

typescript

import { toDefaulted } from 'es-toolkit/compat';

const data = {
  name: undefined,
  age: null,
  active: false,
};
const defaults = {
  name: 'Default',
  age: 18,
  active: true,
  role: 'user',
};

toDefaulted(data, defaults);
// => { name: 'Default', age: null, active: false, role: 'user' }

The original object is not modified; a new object is returned.

typescript

import { toDefaulted } from 'es-toolkit/compat';

const original = { a: 1 };
const result = toDefaulted(original, { a: 2, b: 3 });

console.log(original); // { a: 1 } (not modified)
console.log(result); // { a: 1, b: 3 } (new object)

Parameters

object (object): The target object that will receive default values.
sources (object[]): The source objects that provide default values. Applied in left-to-right order.

Returns

(object): Returns a new object with the default values applied.