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Java Collections unmodifiableSet() Method with Example

Collections Class unmodifiableSet() method: Here, we are going to learn about the unmodifiableSet() method of Collections Class with its syntax and example.
Submitted by Preeti Jain, on February 08, 2020

Collections Class unmodifiableSet() method

• unmodifiableSet() method is available in java.util package.
• unmodifiableSet() method is used to get a non-modifiable view of the given Set (set).
• unmodifiableSet() method is a static method, it is accessible with the class name and if we try to access the method with the class object then also we will not get any error.
• unmodifiableSet() method does not throw an exception at the time of returning an unmodifiable view of the given set.

Syntax:

    public static Set unmodifiableSet(Set set);

Parameter(s):

• Set set – represents the set object for which a non-modifiable view is to be retrieved.

Return value:

The return type of this method is Set, it returns an unmodifiable view of the given set.

Example:

// Java program to demonstrate the example 
// of Set unmodifiableSet() method of Collections


import java.util.*;

public class UnmodifiableSetOfCollections {
    public static void main(String args[]) {
        // Instantiates a linked hashset object
        Set < Integer > lhs = new LinkedHashSet < Integer > ();

        // By using add() method is to add
        // objects in an linked hashset 
        lhs.add(10);
        lhs.add(20);
        lhs.add(30);
        lhs.add(40);
        lhs.add(50);

        // Display LinkedHashSet
        System.out.println("LinkedHashSet: " + lhs);

        // By using unmodifiableSet() method is to
        // represent the array list in an unmodifiable view
        Set us = Collections.unmodifiableSet(lhs);

        // We will get an exception if we 
        // try to add an element in an unmodifiable
        // set (us)

        /* us.add(60); */
    }
}

Output

LinkedHashSet: [10, 20, 30, 40, 50]