What is @types/lodash.merge?
@types/lodash.merge is a TypeScript type definition package for the lodash.merge function, which is part of the Lodash library. Lodash is a popular utility library that provides a wide range of functions for common programming tasks, including object manipulation, array manipulation, and more. The lodash.merge function specifically is used to merge objects, combining their properties recursively.
What are @types/lodash.merge's main functionalities?
Merging Objects
This feature allows you to merge two or more objects recursively. The properties of the source objects are merged into the destination object. If a property at the same key is an object in both source and destination, they are merged recursively.
const _ = require('lodash');
const object1 = { a: 1, b: { c: 2 } };
const object2 = { b: { d: 3 } };
const result = _.merge(object1, object2);
console.log(result); // { a: 1, b: { c: 2, d: 3 } }
Merging Arrays
When merging arrays, lodash.merge will replace the elements of the array in the destination object with the elements of the array in the source object at the same index.
const _ = require('lodash');
const object1 = { a: [1, 2, 3] };
const object2 = { a: [4, 5] };
const result = _.merge(object1, object2);
console.log(result); // { a: [4, 5, 3] }
Merging with Customizer
This feature allows you to provide a customizer function to control how the merge is performed. In this example, the customizer function concatenates arrays instead of replacing them.
const _ = require('lodash');
const object1 = { a: [1, 2, 3] };
const object2 = { a: [4, 5] };
const customizer = (objValue, srcValue) => {
if (Array.isArray(objValue)) {
return objValue.concat(srcValue);
}
};
const result = _.mergeWith(object1, object2, customizer);
console.log(result); // { a: [1, 2, 3, 4, 5] }
Other packages similar to @types/lodash.merge
deepmerge
deepmerge is a library that provides deep merging of JavaScript objects. It is similar to lodash.merge but is a standalone package focused solely on merging objects. It offers a simple API and is often used when only deep merging functionality is needed without the additional utilities provided by Lodash.
merge-deep
merge-deep is another library for deep merging objects. It is lightweight and provides a straightforward API for merging objects recursively. It is similar to lodash.merge but does not come with the additional utilities that Lodash offers.
extend
extend is a library that provides deep and shallow merging of objects. It is similar to lodash.merge but offers both deep and shallow merge options. It is a lightweight alternative for users who need basic merging functionality without the overhead of a larger utility library.