CopyOnWriteArraySet removeIf() method in Java with Examples
Last Updated :
11 Jul, 2025
The
removeIf() method of
CopyonWriteArraySet method removes the element from this CopyOnWriteArraySet that satisfies the specified condition.
Syntax:
public boolean removeIf (Predicate<E> filter)
Parameters: This method accepts a mandatory parameter
filter which is the predicate value based on which elements are removed from this set.
Return Value: This method returns a
boolean value such as true, if the CopyOnWriteArraySet is changed. Else this method returns false.
Exceptions: This method throws
NullPointerException if the specified Predicate filter is null.
Below program illustrates the removeIf() function of CopyOnWriteArrayList class :
Program 1:
Java
// Java Program to illustrate the CopyOnWriteArraySet
// removeIf() method in Java
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create object of CopyOnWriteArraySet
CopyOnWriteArraySet<Integer> ArrSet
= new CopyOnWriteArraySet<Integer>();
// Add elements
ArrSet.add(10);
ArrSet.add(20);
ArrSet.add(30);
ArrSet.add(40);
ArrSet.add(50);
ArrSet.add(60);
ArrSet.add(70);
ArrSet.add(80);
ArrSet.add(90);
// print CopyOnWriteArraySet
System.out.println("CopyOnWriteArraySet: "
+ ArrSet);
// if a number in the set is
// divisible by 3, then remove it
ArrSet.removeIf(number -> number % 3 == 0);
// print updated CopyOnWriteArraySet
System.out.println("Updated CopyOnWriteArraySet: "
+ ArrSet);
}
}
Output:
CopyOnWriteArraySet: [10, 20, 30, 40, 50, 60, 70, 80, 90]
Updated CopyOnWriteArraySet: [10, 20, 40, 50, 70, 80]
Program 2:
Java
// Java Program to illustrate the CopyOnWriteArraySet
// removeIf() method in Java
import java.util.concurrent.CopyOnWriteArraySet;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create object of CopyOnWriteArraySet
CopyOnWriteArraySet<String> ArrSet
= new CopyOnWriteArraySet<String>();
// Add elements
ArrSet.add("GeeksforGeeks");
ArrSet.add("GFG");
ArrSet.add("Geeks");
ArrSet.add("Gfg");
// print CopyOnWriteArraySet
System.out.println("CopyOnWriteArraySet: "
+ ArrSet);
try {
// if a number in the set is
// divisible by 3, then remove it
// This will throw NullPointerException
ArrSet.removeIf(null);
}
catch (Exception e) {
System.out.println(e);
}
}
}
Output:
CopyOnWriteArraySet: [GeeksforGeeks, GFG, Geeks, Gfg]
java.lang.NullPointerException
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