Modifying A Copy Of A Javascript Object Is Causing The Original Object To Change

Are you experiencing a puzzling situation where modifying a copy of a JavaScript object ends up changing the original object? This is a common issue that many developers face, and understanding the underlying mechanics can help you tackle it effectively.

When it comes to JavaScript, objects are passed by reference, which means that when you create a copy of an object, you are actually creating a reference to the original object rather than a completely new object. As a result, any changes made to the copy will also affect the original object because they both point to the same memory address.

To overcome this behavior and ensure that modifying a copy does not impact the original object, you need to create a true copy of the object rather than a reference. One way to achieve this is by using the `Object.assign()` method or the spread operator (`...`) in ES6.

Let's take a closer look at how you can create a copy of a JavaScript object without altering the original object:

Using `Object.assign()`:

const originalObject = { key: 'value' };
const copiedObject = Object.assign({}, originalObject);

copiedObject.key = 'new value';

console.log(originalObject.key); // Output: value
console.log(copiedObject.key);   // Output: new value

In this example, `Object.assign()` creates a new object by copying the properties of the original object into an empty object. This way, you can modify the copied object without affecting the original one.

Using the spread operator (`...`):

const originalObject = { key: 'value' };
const copiedObject = { ...originalObject };

copiedObject.key = 'new value';

console.log(originalObject.key); // Output: value
console.log(copiedObject.key);   // Output: new value

Similarly, the spread operator (`...`) spreads the properties of the original object into a new object, allowing you to make changes to the copied object independently.

By understanding how JavaScript handles object references, you can prevent unintended modifications to the original object when working with copies. Remember to use `Object.assign()` or the spread operator to create true copies that are separate from the original object.

Next time you encounter the issue of modifying a copy of a JavaScript object affecting the original object, apply these techniques to maintain the integrity of your data structures and streamline your development process.

Keep coding confidently and stay tuned for more insightful tech tips!