What is set E in Java?

public interface Set extends Collection A collection that contains no duplicate elements. More formally, sets contain no pair of elements e1 and e2 such that e1. equals(e2) , and at most one null element.

Is set Java?

Set , represents a collection of objects where each object in the Java Set is unique. The Java Set interface is a standard Java interface, and it is a subtype of the Java Collection interface, meaning Set inherits from Collection . You can add any Java object to a Java Set .

What set operation does set addAll () implement?

Method Summary

Modifier and Type Method and Description
boolean addAll(Collection c) Adds all of the elements in the specified collection to this set if they’re not already present (optional operation).
void clear() Removes all of the elements from this set (optional operation).

What is set () in Java?

The set() method of java. util. ArrayList class is used to replace the element at the specified position in this list with the specified element. Syntax: public E set(int index, E element) Parameters: This method takes the following argument as a parameter.

How do you represent a set in Java?


  1. import java.util.*;
  2. public class setExample{
  3. public static void main(String[] args)
  4. {
  5. // creating LinkedHashSet using the Set.
  6. Set data = new LinkedHashSet();
  7. data.add(“JavaTpoint”);
  8. data.add(“Set”);

Is set ordered in Java?

Set is an unordered collection, it doesn’t maintain any order. All the elements of a Set should be unique if you try to insert the duplicate element in Set it would replace the existing value. 3) List implementations: ArrayList, LinkedList etc. Set implementations: HashSet, LinkedHashSet, TreeSet etc.

What is the difference between ADD and addAll in list in Java?

add is used when you need to add single element into collection. addAll is used when you want to add all elements from source collection to your collection.

How do you initialize a set?

Initialize a Set Sets are a mutable collection of distinct (unique) immutable values that are unordered. You can initialize an empty set by using set() . To intialize a set with values, you can pass in a list to set() .

How do you initialize a set in Java in one line?

Initialize HashSet in Java

  1. Using constructor − Pass a collection to Constructor to initialize an HashSet.
  2. Using addAll() − Pass a collection to Collections. addAll() to initialize an HashSet.
  3. Using unmodifiableSet() − Pass a collection to Collections.
  4. Using add() − Using add(element) method of Set.