Java Collections emptySet() Method with Examples

by Online Tutorials Library July 22, 2022

Java Collections emptySet() Method

The emptySet() method of Java Collections class is used to get the Set that has no elements. These empty Set are immutable in nature.

Syntax

Following is the declaration of emptySet() method:

Parameter

This method does not accept any parameter.

Returns

The emptySet() method returns an empty immutable Set.

Exceptions

Compatibility Version

Java 1.5 and above

Example 1

  import java.util.*;  public class CollectionsEmptySetExample1 {  public static void main(String[] args) {       //Create an empty Set          Set EmptySet = Collections.emptySet();       System.out.println(“Empty Set: “+EmptySet);       }    }  

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Output:

Empty Set: []

Example 2

  import java.util.*;  public class CollectionsEmptySetExample2 {  public static void main(String[] args) {  //Create an empty Set        Set EmptySet = Collections.emptySet();        System.out.println(“Created empty immutable Set: “+EmptySet);        //Try to add elements        EmptySet.add(“A”);        EmptySet.add(“B”);        }    }  

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Output:

Created empty immutable Set: []  Exception in thread "main" java.lang.UnsupportedOperationException  at java.base/java.util.AbstractCollection.add(AbstractCollection.java:267)  at myPackage.CollectionsEmptySetExample2.main(CollectionsEmptySetExample2.java:10)

Example 3

  import java.util.*;  public class CollectionsEmptySetExample3 {  public static void main(String[] args) {  //Create an empty Set            Set empSet = Collections.emptySet();        empSet.add(1);        empSet.add(2);            System.out.println(“Created empty immutable Set: “+empSet);             }    }  

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Output:

Exception in thread "main" java.lang.UnsupportedOperationException  at java.base/java.util.AbstractCollection.add(AbstractCollection.java:267)  at myPackage.CollectionsEmptySetExample3.main(CollectionsEmptySetExample3.java:8)

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Java Collections emptySet() Method with Examples

Java Collections emptySet() Method

Syntax

Parameter

Returns

Exceptions

Compatibility Version

Example 1

Example 2

Example 3

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