Cloning an Object with Lodash – onlinecode

Lodash’s clone() function is a powerful utility for shallow cloning generic objects. The Object.assign() function or the spread operator are the canonical methods for shallow copying a POJO. But _.clone() has some additional functionality built in that may make it a better choice for your use case.

Cloning an Array

Object.assign() and _.clone() behave similarly when
copying a plain old JavaScript object (POJO). But what
about cloning an array?

const arr = ['a', 'b', 'c'];

// 'Object.assign()' will copy all the array properties
// into a POJO
Object.assign({}, arr); // { '0': 1, '1': 2, '2': 3 }

// But '_.clone()' is smart enough to clone an array
_.clone(arr); // ['a', 'b', 'c']

Cloning an Instance of a Class

Another benefit of _.clone() is that the cloned object
will have the same ES6 class as the original object. The Object.assign() function always returns a POJO.

class MyClass {
  constructor(val) {
    this.val = val;
  }
}

const obj = new MyClass(42);

// 'Object.assign()' **always** returns a POJO. It
// doesn't actually create a new instance of the class.
Object.assign({}, obj) instanceof MyClass; // false

// '_.clone()' retains the original object's class.
_.clone(obj) instanceof MyClass; // true

Takeaways

If you need to clone a POJO, you don’t need Lodash. Just use {...obj} or Object.assign({}, obj). But _.clone() is  handy if you find yourself needing to clone class instances, or just want to be able to clone an arbitrary object without checking whether it is an array.

Lodash is a JavaScript library which provides utility functions for common programming tasks using the functional programming paradigm. Lodash is a JavaScript library that helps programmers write more concise and maintainable JavaScript. It can be broken down into several main areas: Utilities: for simplifying common programming tasks such as determining type as well as simplifying math operations.