What is the Difference Between Set and WeakSet in Javascript
In JavaScript, sets are used to store unique values of any data type. However, there are two types of sets: Set and WeakSet. Both have their own unique features that make them useful in different situations. In this tutorial, we will explore the differences between Set and WeakSet in JavaScript.
Definition and Syntax
A Set is a collection of unique values of any data type, where duplicates are not allowed. It is defined as follows:
let set = new Set([iterable]);
On the other hand, a WeakSet is a collection of objects only, where duplicates are not allowed. It is defined as follows:
let weakSet = new WeakSet([iterable]);
Memory Management
Sets are reference-based data structures that store their elements by reference. When a Set is created, references to the added elements are stored in the Set. If an element is deleted from the Set, the reference is still held by the Set, which can lead to memory leaks if not handled correctly.
WeakSets, on the other hand, are also reference-based data structures, but they hold weak references to the elements they store. This means that if an object stored in a WeakSet is no longer referenced anywhere else, it can be garbage collected. This makes WeakSets useful in situations where memory management is a concern.
Iterable Objects
Both Set and WeakSet can accept iterable objects as arguments. Iterable objects are objects that can be iterated over, such as arrays or strings. When an iterable object is passed as an argument to a Set or WeakSet constructor, its values are added to the Set or WeakSet.
Methods
Both Set and WeakSet have similar methods for adding, deleting, and checking the presence of elements. The methods include:
- add(value): Adds a new value to the Set or WeakSet.
- delete(value): Deletes a value from the Set or WeakSet.
- has(value): Returns true if the value is in the Set or WeakSet.
However, WeakSets do not have a size property or a way to iterate over their elements, as they only store object references.
Use Cases
Sets are useful when dealing with unique values of any data type, such as removing duplicates from an array or checking if a value exists in a collection. WeakSets, on the other hand, are useful for storing object references where memory management is a concern, such as in a cache where objects can be removed when they are no longer needed.
In conclusion, Sets and WeakSets are both useful data structures in JavaScript, but they have different use cases. Sets are used to store unique values of any data type, while WeakSets are used to store object references where memory management is a concern. By understanding the differences between the two, you can choose the appropriate data structure for your specific use case.
