What is The Set Interface

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The Set interface provides methods for accessing the elements of a finite mathematical set. Sets do not allow duplicate elements.

The Set interface in Java is a part of the Java Collections Framework and is part of the java.util package. It extends the Collection interface and represents a collection of unique elements. Unlike a List, a Set does not allow duplicate elements.

Key characteristics of the Set interface include:

  1. Uniqueness: A Set cannot contain duplicate elements. If you attempt to add an element that is already present, the set will not be modified, and the add operation will return false.
  2. No specific order: Unlike some other collection types, such as Lists, Sets do not guarantee any specific order of elements.
  3. Methods: The Set interface includes methods like add(), remove(), contains(), size(), and others common to collections.

Here’s a simple example of using a Set in Java:

java
import java.util.HashSet;
import java.util.Set;public class SetExample {
public static void main(String[] args) {
// Creating a Set using HashSet
Set<String> stringSet = new HashSet<>();

// Adding elements to the Set
stringSet.add(“Apple”);
stringSet.add(“Banana”);
stringSet.add(“Orange”);
stringSet.add(“Apple”); // Duplicate element, won’t be added

// Displaying elements of the Set
System.out.println(“Set elements: “ + stringSet);
}
}

In this example, “Apple” is added only once, even though it’s attempted to be added twice, because Sets do not allow duplicates. The output will show only unique elements.