Sentry Answers>JavaScript>

What is the most efficient way to deep clone an object in JavaScript?

What is the most efficient way to deep clone an object in JavaScript?

David Y.

The ProblemJump To Solution

What is the most efficient way to deep clone an object in JavaScript?

The Solution

Several methods for deep cloning objects in JavaScript have been invented over the years, with varying efficiency and effectiveness. Modern browsers provide the structuredClone() function, which will create a deep clone of an object provided to it using the structured clone algorithm. A code example:

Click to Copy
const person = { firstName: "John", lastName: "Doe", age: 35, purchaseHistory: [ { productName: "apple", quantity: 5, datePurchased: new Date() }, { productName: "banana", quantity: 3, datePurchased: new Date() }, { productName: "pear", quantity: 4, datePurchased: new Date() } ] }; const clone = structuredClone(person); console.assert(clone !== person); // two distinct objects console.assert(clone.firstName === "John"); // same values

Note that structuredClone() does not support object properties that are functions or DOM nodes, and will throw a DataCloneError if these are found in the object provided for cloning.

  • ResourcesImprove Web Browser Performance - Find the JavaScript code causing slowdowns
  • ResourcesJavaScript Frontend Error Monitoring 101
  • Syntax.fm logo
    Listen to the Syntax Podcast

    Tasty treats for web developers brought to you by Sentry. Get tips and tricks from Wes Bos and Scott Tolinski.

    SEE EPISODES

Loved by over 4 million developers and more than 100,000 organizations worldwide, Sentry provides code-level observability to many of the world’s best-known companies like Disney, Peloton, Cloudflare, Eventbrite, Slack, Supercell, and Rockstar Games. Each month we process billions of exceptions from the most popular products on the internet.

© 2024 • Sentry is a registered Trademark
of Functional Software, Inc.