How to create an Empty Set in Java - Step by Step Examples

How to create an Empty Set in Java ?

Answer

To create an empty set in Java, you can use the Collections.emptySet method or the new HashSet constructor with no arguments.

✐ Examples

1 Create an Empty Set Using Collections.emptySet

In this example,

We use the Collections.emptySet method which is a standard library method in Java that returns an empty, immutable (read-only) set.
We declare a variable named set1 of type Set<String> and assign it the result of the Collections.emptySet method.
The Collections.emptySet method returns a set that is parameterized with the type of String.
We then print the set1 to the standard output to verify its contents.

Java Program

import java.util.Collections;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        Set<String> set1 = Collections.emptySet();
        System.out.println("Contents of set1: " + set1);
    }
}

Output

Contents of set1: []

2 Create an Empty Set Using new HashSet Constructor

In this example,

We use the new HashSet constructor which is a standard library method in Java that creates an empty, mutable (modifiable) set.
We declare a variable named set2 of type Set<String> and assign it the result of the new HashSet<> constructor.
The new HashSet<> constructor creates a set that is parameterized with the type of String.
We then print the set2 to the standard output to verify its contents.

Java Program

import java.util.HashSet;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        Set<String> set2 = new HashSet<>();
        System.out.println("Contents of set2: " + set2);
    }
}

Output

Contents of set2: []

Summary

In this tutorial, we learned How to create an Empty Set in Java language with well detailed examples.

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How to create an Empty Set in Java - Step by Step Examples

How to create an Empty Set in Java ?

Answer

✐ Examples

1 Create an Empty Set Using Collections.emptySet

Java Program

Output

2 Create an Empty Set Using new HashSet Constructor

Java Program

Output

Summary

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