The removeAll() method of java.util.concurrent.ConcurrentSkipListSet is an in-built function in Java which returns removes from this set all of its elements that are contained in the specified collection. If the specified collection is also a set, this operation effectively modifies this set so that its value is the asymmetric set difference of the two sets.
Syntax:
public boolean removeAll(Collection> c)
Parameter: The function accepts a single parameter c
Return Value: The function returns true if this set changed as a result of the call.
Exception: The function throws the following exceptions:
Below programs illustrate the ConcurrentSkipListSet.removeAll() method:
Program 1:
// Java program to demonstrate removeAll() // method of ConcurrentSkipListSet import java.util.concurrent.*;
import java.util.ArrayList;
import java.util.List;
class ConcurrentSkipListSetremoveAllExample1 {
public static void main(String[] args)
{
// Initializing the List
List<Integer> list = new ArrayList<Integer>();
// Adding elements in the list
for ( int i = 1 ; i <= 10 ; i += 2 )
list.add(i);
// Contents of the list
System.out.println( "Contents of the list: " + list);
// Initializing the set
ConcurrentSkipListSet<Integer>
set = new ConcurrentSkipListSet<Integer>();
// Adding elements in the set
for ( int i = 1 ; i <= 10 ; i++)
set.add(i);
// Contents of the set
System.out.println( "Contents of the set: " + set);
// Remove all elements from the set which are in the list
set.removeAll(list);
// Contents of the set after removal
System.out.println( "Contents of the set after removal: "
+ set);
}
} |
Contents of the list: [1, 3, 5, 7, 9] Contents of the set: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] Contents of the set after removal: [2, 4, 6, 8, 10]
Program 2: Program to show NullPOinterException in removeAll().
// Java program to demonstrate removeAll() // method of ConcurrentSkipListSet import java.util.concurrent.*;
import java.util.ArrayList;
import java.util.List;
class ConcurrentSkipListSetremoveAllExample1 {
public static void main(String[] args)
{
// Initializing the set
ConcurrentSkipListSet<Integer>
set = new ConcurrentSkipListSet<Integer>();
// Adding elements in the set
for ( int i = 1 ; i <= 10 ; i++)
set.add(i);
// Contents of the set
System.out.println( "Contents of the set: " + set);
try {
// Remove all elements from the set which are null
set.removeAll( null );
}
catch (Exception e) {
System.out.println( "Exception: " + e);
}
}
} |
Contents of the set: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] Exception: java.lang.NullPointerException
Reference: