util-extend

What is util-extend?

The util-extend npm package is a utility library that provides functionality to extend objects. It is commonly used to merge properties from one or more source objects into a target object, effectively combining their properties.

What are util-extend's main functionalities?

Basic Object Extension

This feature allows you to extend a target object with properties from a source object. In this example, the target object { a: 1 } is extended with the source object { b: 2 }, resulting in { a: 1, b: 2 }.

const extend = require('util-extend');
const target = { a: 1 };
const source = { b: 2 };
const result = extend(target, source);
console.log(result); // { a: 1, b: 2 }

Multiple Source Objects

This feature allows you to extend a target object with properties from multiple source objects. In this example, the target object { a: 1 } is extended with source objects { b: 2 } and { c: 3 }, resulting in { a: 1, b: 2, c: 3 }.

const extend = require('util-extend');
const target = { a: 1 };
const source1 = { b: 2 };
const source2 = { c: 3 };
const result = extend(target, source1, source2);
console.log(result); // { a: 1, b: 2, c: 3 }

Overwriting Properties

This feature allows you to overwrite properties in the target object with properties from the source object. In this example, the target object { a: 1, b: 2 } is extended with the source object { b: 3, c: 4 }, resulting in { a: 1, b: 3, c: 4 }.

const extend = require('util-extend');
const target = { a: 1, b: 2 };
const source = { b: 3, c: 4 };
const result = extend(target, source);
console.log(result); // { a: 1, b: 3, c: 4 }

Other packages similar to util-extend

lodash

Lodash is a modern JavaScript utility library delivering modularity, performance, and extras. It provides a wide range of utility functions, including object extension through its `_.assign` and `_.merge` methods. Compared to util-extend, Lodash offers a more comprehensive set of utilities for various programming tasks.

extend

The extend package is a simple utility for deep cloning and extending objects. It is similar to util-extend in that it allows for merging properties from source objects into a target object. However, extend also supports deep merging, which means it can recursively merge nested objects.

deepmerge

Deepmerge is a library for deep merging of JavaScript objects. It is particularly useful for merging complex nested objects, which is something util-extend does not handle. Deepmerge is a good choice when you need to merge objects with nested structures.

README

util-extend

The Node object extending function that Node uses for Node!

Usage

var extend = require('util-extend');
function functionThatTakesOptions(options) {
  var options = extend(defaults, options);
  // now any unset options are set to the defaults.
}