An array is a data structure that stores a collection of elements, such as strings, numbers, or objects. It is essentially a list of values that are indexed with a numerical value, starting at 0. Arrays are mutable, which means that their contents can be modified.
let fruits = ["apple", "banana", "orange"];
In the example above, we have created an array named fruits that contains three elements.
A set is a data structure that stores a collection of unique elements. Unlike arrays, sets do not have a numerical index associated with each element. Instead, each element in a set is unique, and the set ensures that there are no duplicate elements.
let mySet = new Set(["apple", "banana", "orange"]);
In the example above, we have created a set named mySet that contains three unique elements.
Main Differences Between Sets and Arrays
- Duplicates: Arrays can contain duplicate elements, whereas sets cannot. If you try to add a duplicate element to a set, it will simply be ignored.
- Order: Arrays are ordered collections of elements, which means that each element has a specific index. Sets, on the other hand, are unordered collections of unique elements. This means that the order in which you add elements to a set is not preserved.
- Mutability: Arrays are mutable, which means that you can add or remove elements from them. Sets are also mutable, but you can only add or remove elements – you cannot change an existing element in a set.
- Indexing: Arrays are accessed using their index, which is a numerical value that starts at 0. Sets, on the other hand, do not have an index associated with their elements.
- Performance: In terms of performance, sets are generally faster than arrays when it comes to checking for the presence of an element. This is because sets are implemented using hash tables, which allow for faster lookups.
By understanding the differences between arrays and sets, you can choose the appropriate data structure for your specific programming needs.