CopyOnWriteArraySet size() method in Java

Last Updated : 11 Jul, 2025
The size() method of CopyOnWriteArraySet returns the size of the Set. It returns the number of elements in the current Set. Syntax:
public int size()
Return Value: The function returns the number of elements in the current Set. Below programs illustrate the above function: Program 1: Java
// Java Program to illustrate the CopyOnWriteArraySet
// size() 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>();

        // print CopyOnWriteArraySet
        System.out.println("CopyOnWriteArraySet: "
                           + ArrSet);

        // size value print
        System.out.println("size of ArrSet: "
                           + ArrSet.size());

        // Add elements
        ArrSet.add(32);
        ArrSet.add(67);
        ArrSet.add(98);
        ArrSet.add(100);

        // print CopyOnWriteArraySet
        System.out.println("CopyOnWriteArraySet: "
                           + ArrSet);

        // size value print
        System.out.println("size of ArrSet: "
                           + ArrSet.size());
    }
}
Output:
CopyOnWriteArraySet: []
size of ArrSet: 0
CopyOnWriteArraySet: [32, 67, 98, 100]
size of ArrSet: 4
Program 2: Java
// Java Program to illustrate the CopyOnWriteArraySet
// size() 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("gopal");
        ArrSet.add("gfg");
        ArrSet.add("jgec");
        ArrSet.add("sudo");

        // print CopyOnWriteArraySet
        System.out.println("CopyOnWriteArraySet: "
                           + ArrSet);

        // size value print
        System.out.println("size of ArrSet: "
                           + ArrSet.size());
    }
}
Output:
CopyOnWriteArraySet: [gopal, gfg, jgec, sudo]
size of ArrSet: 4
Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CopyOnWriteArraySet.html#size--
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