Set clear() method in Java with Examples

The Java.util.Set.clear() method is used to remove all the elements from a Set. Using the clear() method only clears all the element from the set and not deletes the set. In other words, we can say that the clear() method is used to only empty an existing Set.

Syntax:

void clear()

Parameters: The method does not take any parameter

Return Value: The method does not returns any value.

Below program illustrate the Java.util.method.clear() method:

// Java code to illustrate clear()
import java.io.*;
import java.util.*;

public class SetDemo {
    public static void main(String args[])
    {
        // Creating an empty Set
        Set<String> st = new HashSet<String>();

        // Use add() method to add elements into the Set
        st.add("Welcome");
        st.add("To");
        st.add("Geeks");
        st.add("4");
        st.add("Geeks");

        // Displaying the Set
        System.out.println("Initial Set: " + st);

        // Clearing the Set using clear() method
        st.clear();

        // Displaying the final Set after clearing;
        System.out.println("The final set: " + st);
    }
}

Output:

Initial Set: [4, Geeks, Welcome, To]
The final set: []

Reference: https://docs.oracle.com/javase/7/docs/api/java/util/Set.html#clear()