Java Collections - emptySet() Method
The java.util.Collections.emptySet() method returns an empty set (immutable). This set is serializable.
Syntax
public static final <T> List<T> emptySet()
Here, T is the type of element, if there were any, in the set.
Parameters
No parameter is required.
Return Value
Returns an empty immutable set.
Exception
NA.
Example:
In the example below, the java.util.Collections.emptySet() method is used to create an empty immutable set.
import java.util.*;
public class MyClass {
public static void main(String[] args) {
//creating an empty set
Set<Integer> MySet = Collections.emptySet();
//print the content of the set
System.out.println("MySet contains: " + MySet);
//populating the set
//as the set is immutable,
//the exception is thrown
MySet.add(10);
MySet.add(20);
MySet.add(30);
MySet.add(40);
MySet.add(50);
//print the content of the set
System.out.println("MySet contains: " + MySet);
}
}
The output of the above code will be:
MySet contains: []
Exception in thread "main" java.lang.UnsupportedOperationException
at java.base/java.util.AbstractCollection.add(AbstractCollection.java:267)
at MyClass.main(MyClass.java:14)
❮ Java.util - Collections
