ListSet in Scala

A set is a collection which only contains unique items which are not repeatable and a list is a collection which contains immutable data. In scala, ListSet class implements immutable sets using a list-based data structure. Elements are stored in reversed insertion order, That means the newest element is at the head of the list. It maintains insertion order. Listset is used only for a small number of elements. We can create empty ListSet either by calling the constructor or by applying the function ListSet.empty. It’s iterate and traversal methods visit elements in the same order in which they were first inserted. 

Syntax:

var ListSetName = ListSet(element1, element2, element3, ....)  

Operations with ListSet

Initialize a ListSet : Below is the example to create or initialize ListSet. 

Output:

Initializing an immutable ListSet 
Elements of listSet1 = ListSet(Scala, Article, GeeksForGeeks)

Check specific elements in ListSet : 

Output:

Initializing an immutable ListSet 
Elements of listSet1 = ListSet(Scala, Article, GeeksForGeeks)
Check elements of immutable ListSet
GeeksForGeeks = true
Student = false
Scala = true

Adding an elements in ListSet : We can add an element in ListSet by using + operator. below is the example of adding an element in ListSet. 

Output:

Initializing an immutable ListSet 
Elements of listSet1 = ListSet(Scala, Article, GeeksForGeeks)
Add element of immutable ListSet 
Adding element java to ListSet ListSet(Java, Scala, Article, GeeksForGeeks)

Adding two ListSet : We can add two ListSet by using ++ operator. below is the example of adding two ListSet. 

Output:

Initializing an immutable ListSet 
Elements of listSet1 = ListSet(Scala, Article, GeeksForGeeks)
After adding two lists ListSet(Java, Csharp, Scala, Article, GeeksForGeeks)

Remove element from the ListSet : We can remove an element in ListSet by using – operator. below is the example of removing an element in ListSet. 

Output:

Initializing an immutable ListSet 
Elements of listSet1 = ListSet(Scala, Article, GeeksForGeeks)
Remove element from the ListSet 
After removing element from listset = ListSet(Scala, GeeksForGeeks)

Initialize an empty ListSet : 

Output:

Initialize an empty ListSet
String type empty ListSet = ListSet()

Note: We can create empty ListSet either by applying the function ListSet.empty or by calling the constructor .

ListSet in Scala is an immutable collection that represents a set of elements as an ordered list. ListSet provides constant time operations for adding and removing elements, and it preserves the order of elements in the list.

Here are some key features and usage examples of ListSet:

1. ListSet is immutable, meaning that its contents cannot be modified after creation.
2. ListSet provides efficient constant time operations for adding and removing elements, as well as set operations such as union, intersection, and difference.
3. ListSet preserves the order of elements in the list, making it useful for scenarios where the order of elements is important.
4. ListSet can be used in a variety of scenarios, including removing duplicates from a list, checking for membership of elements in a set, and performing set operations on two or more sets.

Here’s an example code snippet that demonstrates the usage of ListSet in Scala:

Original set: ListSet(5, 4, 3, 2, 1)
Updated set: ListSet(6, 5, 4, 3, 2, 1)
Removed set: ListSet(6, 5, 3, 2, 1)
Contains element: true
Union set: ListSet(4, 7, 6, 5, 3, 2, 1)

In this example, we create a new ListSet and add, remove, and check for membership of elements in it. We also get the union of the ListSet with another ListSet. As we can see from the output, the ListSet preserves the order of elements in the list, and the set operations return new sets without modifying the original sets.