Hidden Features Of Javascript Closed

You may already be familiar with the basics of JavaScript, the popular programming language used for creating dynamic and interactive web pages. However, did you know that there are some hidden features in JavaScript that can make your code more efficient and your development process smoother?

One such feature is the "closed" property in JavaScript objects. This property allows you to define an object as non-extensible, meaning that you cannot add new properties to it. While this may seem restrictive at first, it can be incredibly useful in certain situations where you want to ensure that the structure of an object remains fixed.

To create a closed object in JavaScript, you can use the Object.preventExtensions() method. This method takes an object as an argument and prevents any new properties from being added to it. Here's an example:

let closedObject = { property1: 'value1', property2: 'value2' };
Object.preventExtensions(closedObject);

closedObject.property3 = 'value3'; // This will throw an error in strict mode

In this example, attempting to add a new property `property3` to the `closedObject` will result in an error because the object has been defined as closed using `Object.preventExtensions()`.

Another interesting aspect of closed objects in JavaScript is that they can still be modified in other ways, such as changing the values of existing properties or deleting properties. This means that while you cannot expand the object by adding new properties, you can still work with the properties that are already defined.

Closed objects can also be helpful in situations where you want to create read-only objects. By defining an object as closed, you can prevent accidental modifications to its properties, helping to maintain the integrity of the object in your code.

It's worth noting that closed objects are different from sealed objects in JavaScript. Sealed objects prevent any changes to the object's structure, including adding, deleting, or modifying properties, whereas closed objects only restrict the addition of new properties.

In conclusion, utilizing the hidden feature of closed objects in JavaScript can provide an extra layer of control and security to your code. By preventing the addition of new properties to specific objects, you can ensure that the structure remains consistent and avoid unexpected modifications. Next time you're working on a project that requires strict object definitions, consider using closed objects to enhance your coding practices and streamline your development process.