The Java.util.AbstractCollection.removeAll(Collection col) method is used to remove all the elements from the AbstractCollection, present in the collection specified.
Syntax:
AbstractCollection.removeAll(Collection col)
Parameters: This method accepts a mandatory parameter col which is the collection whose elements are to be removed from the AbstractCollection.
Return Value: This method returns true if the AbstractCollection is altered due to the operation at all, else False.
Exception: The method throws NullPointerException if the specified collection is null.
Below programs illustrate the Java.util.AbstractCollection.removeAll(Collection col) method:
Program 1:
// Java code to illustrate removeAll() import java.util.*;
public class AbstractCollectionDemo {
public static void main(String args[])
{
// Creating an empty AbstractCollection
AbstractCollection<String> collection
= new ArrayList<String>();
// Use add() method to add
// elements in the AbstractCollection
collection.add( "Geeks" );
collection.add( "for" );
collection.add( "Geeks" );
collection.add( "10" );
collection.add( "20" );
// Output the AbstractCollection
System.out.println( "AbstractCollection: "
+ collection);
// Creating an empty AbstractCollection
AbstractCollection<String> colcollection
= new ArrayList<String>();
// Use add() method to add
// elements in the AbstractCollection
colcollection.add( "Geeks" );
colcollection.add( "for" );
colcollection.add( "Geeks" );
// Remove the head using remove()
boolean changed
= collection.removeAll(colcollection);
// Print the result
if (changed)
System.out.println( "Collection removed" );
else
System.out.println( "Collection not removed" );
// Print the final AbstractCollection
System.out.println( "Final AbstractCollection: "
+ collection);
}
} |
AbstractCollection: [Geeks, for, Geeks, 10, 20] Collection removed Final AbstractCollection: [10, 20]
Program 2:
// Java code to illustrate removeAll() import java.util.*;
public class AbstractCollectionDemo {
public static void main(String args[])
{
// Creating an empty AbstractCollection
AbstractCollection<Integer> collection
= new ArrayList<Integer>();
// Use add() method to
// add elements in the AbstractCollection
collection.add( 1 );
collection.add( 2 );
collection.add( 3 );
collection.add( 10 );
collection.add( 20 );
// Output the AbstractCollection
System.out.println( "AbstractCollection: "
+ collection);
// Creating an empty AbstractCollection
AbstractCollection<Integer> colcollection
= new ArrayList<Integer>();
// Use add() method to add elements
// in the AbstractCollection
colcollection.add( 30 );
colcollection.add( 40 );
colcollection.add( 50 );
// Remove the head using remove()
boolean changed
= collection.removeAll(colcollection);
// Print the result
if (changed)
System.out.println( "Collection removed" );
else
System.out.println( "Collection not removed" );
// Print the final AbstractCollection
System.out.println( "Final AbstractCollection: "
+ collection);
}
} |
AbstractCollection: [1, 2, 3, 10, 20] Collection not removed Final AbstractCollection: [1, 2, 3, 10, 20]