How to clone an object in JavaScript

Cloning an object in JavaScript allows you to create a duplicate copy of the original object. It's useful when you want to work with a separate instance of the object without modifying the original. JavaScript provides several methods to clone objects, such as using the spread operator (...), Object.assign(), or JSON.parse() and JSON.stringify(). These methods enable you to create shallow clones that replicate the properties of the original object. For more complex scenarios requiring deep cloning, libraries like Lodash or specialized functions like clone() offer convenient solutions. Cloning objects gives you the flexibility to manipulate data independently and avoid unintended side effects.

When cloning an object, it's essential to understand the distinction between shallow and deep cloning. Shallow cloning creates a new object that references the same nested objects or arrays as the original. Any changes made to the nested references will affect both the original and cloned objects. Deep cloning, on the other hand, creates a completely independent copy, including all nested objects and arrays. It ensures that modifications to the cloned object do not affect the original. However, deep cloning can be more resource-intensive and may have limitations, such as not supporting functions or symbol properties. Carefully consider the depth of cloning required and choose the appropriate method or library to suit your specific use case.

Ways to clone an object in JavaScript

To clone an object in JavaScript, you can use various approaches depending on your specific requirements. Here are a few common methods:

1. Using the Spread Operator (...)

const originalObject = { key: "value" };
const clonedObject = { ...originalObject };

This method creates a new object and spreads the properties of the original object into it. However, keep in mind that this is a shallow clone, meaning nested objects or arrays will still be references to the original object.

2. Using Object.assign()

const originalObject = { key: "value" };
const clonedObject = Object.assign({}, originalObject);

Here, Object.assign() creates a new empty object as the target and assigns the properties from the original object to the target. Again, this is a shallow clone.

3. Using JSON.parse() and JSON.stringify()

const originalObject = { key: "value" };
const clonedObject = JSON.parse(JSON.stringify(originalObject));

This method converts the original object to a JSON string using JSON.stringify(), and then parses the JSON string back into a new object using JSON.parse(). This approach creates a deep clone, including nested objects and arrays. However, it has limitations, such as not supporting functions or symbol properties.

4. Using Object.create()

const originalObject = { key: "value" };
const clonedObject = Object.create(Object.getPrototypeOf(originalObject), Object.getOwnPropertyDescriptors(originalObject));

This method uses Object.create() to create a new object with the prototype of the original object and copies the property descriptors from the original object using Object.getOwnPropertyDescriptors(). This approach creates a shallow clone.

5. Using the lodash.cloneDeep() method (from the Lodash library)

const originalObject = { key: "value" };
const clonedObject = _.cloneDeep(originalObject);

If you have the Lodash library available in your project, you can use _.cloneDeep() to create a deep clone of the original object. This method ensures that all nested objects and arrays are cloned recursively.

6. Using the Object.fromEntries() method (for shallow cloning)

const originalObject = { key: "value" };
const clonedObject = Object.fromEntries(Object.entries(originalObject));

This method uses Object.entries() to get an array of key-value pairs from the original object and then Object.fromEntries() to convert it back into a new object. This approach creates a shallow clone.

7. Using third-party libraries like clone() (from the clone library) or clone() (from the rfdc library)

const originalObject = { key: "value" };
const clonedObject = clone(originalObject); // Using clone library
// or
const clonedObject = clone(originalObject); // Using rfdc library

These libraries provide specialized cloning functions that handle deep cloning with support for functions, symbols, and other complex data types.

It’s important to note that when cloning objects with references to other objects or complex data types, you may need to consider deep cloning techniques to ensure the complete independence of the cloned object.

Choose the method that best fits your requirements, considering whether you need a shallow or deep clone, and whether you want to include complex data types or functions in the cloned object.

Happy Coding..!!