In JavaScript, Set and Array is common data structures used to store collections of data. These data structures are different because of their unique features. Both Set and Array are used to store data in an ordered way. The main difference between a set and an array is that data stored in a set is unique an no duplication is allowed whereas arrays allow the insertion of duplicate data.
Let us look at the implementation of both of these data structures.
JavaScript Set: Sets are used to store collections of unique value without allowing duplication. The set is similar to the array and supports both insertion and deletion methods of the array. Sets are faster than arrays in terms of searching as they use a hash table internally for storing data and can be used to replace duplicates from other data types.
Syntax:
new Set([it]);
Example: In this example, we will implement a set
Javascript
let sample = new Set();sample.add("Hello");sample.add(1)sample.add("Bye")sample.add("@");for (let item of sample) { console.log(item);} |
Output:
Hello 1 Bye @
JavaScript Array: The array is a data structure that is used to store data in a sequential manner of the same type. Arrays allow duplication of data and data is indexed which means that the data can be accessed according to its unique index.
Syntax:
let arrayName = [value1, value2, ...]; // Method 1 let arrayName = new Array(); // Method 2
Example: In this example, we will implement an array and access its element.
Javascript
let sample = new Array();sample.push("Hello");sample.push("1")sample.push("Bye")sample.push("@");console.log(sample);console.log(sample[3]) |
Output:
['Hello', '1', 'Bye', '@'] @
What to use?
The usage of the data structure depends on the requirement. If you want to have a unique list of items where each element can only be present once and also want faster access to the elements then use set otherwise if you want to access the element according to its insertion order then use array.
| Set | Array |
|---|---|
| Collection of unique value | Sequential collection of data |
| Duplication is not allowed | Duplication is allowed |
| Accessing elements is faster | Searching is slow comparatively |
| Elements are accessed using hash table | Elements are accessed using index |
