Delete operator vs map delete method

Delete operator vs map delete method

Manipulating the properties of JavaScript objects is a daily task for many developers. However, there are cases where efficiency and performance can be significantly improved, and one solution is to turn an object into a map. In this article, we'll take a look at what the benefits of using maps are.

Differences between delete operator and map

It often happens that we need to add or delete properties from an object. The standard way is to use the delete operator, as in the following example:

const user = {};

user.firstName = "Jan";
user.petName = "Pimpek";

delete user.petName;

user.nickname = "Janeczek01";

delete user.firstName;

Although this code works fine, it can be inefficient, especially if there are a lot of delete operations. Is there a better way?

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Converting to Map

The solution is to turn the object into a map. A map is a data structure available in JavaScript that offers a more efficient way to manage data, including operations to add and remove elements. Here's how to do it:

const user = new Map();

user.set("firstName", "Jan");
user.set("petName", "Pimpek");


user.set("nickname", "Janeczek01");


Actually, what for?

Performance: Map operations are much more efficient than delete operations on objects. For large data sets, the performance difference can be significant. Maps are optimized for fast access and changing values under specific keys.

Clarity and security: Maps offer a clearer and more secure way to manage data. In objects, properties can be overwritten or deleted accidentally or unintentionally, which can lead to errors. In maps, access to keys is controlled by set and delete methods, minimizing the risk of such problems.

Code portability: Map-based code is more portable and readable. Other programmers will find it easier to understand what is going on and can easily adapt to such a convention. Maps are a more general and understandable way to store data than objects with multiple properties.
Ability to use arbitrary keys: In maps, any data type can be used as keys, while in objects, keys are always strings. This means that more complex data, such as objects or functions, can be stored as keys in maps.

Scalability: As the number of operations on data increases, a map remains an efficient tool, while using delete on objects can lead to a drop in performance.

It is worth noting that objects and maps have different uses, and it will not always be necessary or beneficial to replace objects with maps. The decision between the two depends on the specific situation and needs of the project, but the use of maps is usually recommended for data management, especially when delete operations become problematic from a performance and security perspective.