HashSet remove() method is used to remove a particular element from a HashSet. Note that it is only after JDK version 1.2 and ahead, and will throw compilation errors before in version JDK 1 and JDK1.1.
Note: This method returns true if the specified element is present in the HashSet otherwise it returns boolean false.
Syntax:
HashSet.remove(Object O)
Parameters: The parameter O is of the type of HashSet and specifies the element to be removed from the HashSet.
Return Value: Boolean true and false
Example 1:
Java
// Java code to illustrate // HashSet.remove() method // over String Elements // Importing required classes import java.util.*;
// Main class // HashSet demo public class GFG {
// Main driver method
public static void main(String args[])
{
// Creating an empty HashSet
// Declaring object of string type
HashSet<String> set = new HashSet<String>();
// Adding custom input elements into the Set
// using add() method
set.add( "Welcome" );
set.add( "To" );
set.add( "Geeks" );
set.add( "For" );
set.add( "Geeks" );
// Displaying the HashSet(object elements)
System.out.println( "HashSet: " + set);
// Removing elements
// using remove() method
set.remove( "Geeks" );
set.remove( "For" );
set.remove( "Welcome" );
// Now displaying the HashSet after removal
// of elements from it
System.out.println(
"HashSet after removing elements: " + set);
}
} |
Output
HashSet: [Geeks, For, Welcome, To] HashSet after removing elements: [To]
Example 2:
Java
// Java code to illustrate remove() // method of Hashset class // over Integer Elements // Importing required classes import java.util.*;
// Main class public class GFG {
// Main driver method
public static void main(String args[])
{
// Creating an empty HashSet
// Declaring object of integer type
HashSet<Integer> set = new HashSet<Integer>();
// Adding custom input elements into the Set
// using add() method
set.add( 5 );
set.add( 3 );
set.add( 1 );
set.add( 4 );
set.add( 3 );
// Displaying the HashSet(object elements)
System.out.println( "HashSet: " + set);
// Removing elements
// using remove() method
set.remove( 3 );
set.remove( 1 );
// Now displaying the HashSet after removal
// of elements from it
System.out.println(
"HashSet after removing elements: " + set);
}
} |
Output
HashSet: [1, 3, 4, 5] HashSet after removing elements: [4, 5]