The contains(E e) method of CopyOnWriteArraySet checks if a given element is present in the Set or not.
Syntax:
public boolean contains(Object o)
Parameters: The function accepts a single mandatory parametero which specifies the element whose appearance is to be checked in the Set.
Return Value: The function returns true if the element is present else it returns false.
Below programs illustrate the above function:
Program 1:
// Java Program to illustrate the CopyOnWriteArraySet// contains() 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(32);        ArrSet.add(67);        ArrSet.add(67);        ArrSet.add(100);          // print CopyOnWriteArraySet        System.out.println("CopyOnWriteArraySet: "                           + ArrSet);          // check if 100 is present        // using contains() function        if (ArrSet.contains(100))            System.out.println("100 is "                               + "present in the Set");        else            System.out.println("100 is "                               + "not present in the Set");          // check if 20 is present        // using contains() function        if (ArrSet.contains(20))            System.out.println("20 is "                               + "present in the Set");        else            System.out.println("20 is "                               + "not present in the Set");    }} |
Output:
CopyOnWriteArraySet: [32, 67, 100] 100 is present in the Set 20 is not present in the Set
Program 2:
// Java Program to illustrate the CopyOnWriteArraySet// contains() 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("geeks");        ArrSet.add("gfg");        ArrSet.add("jgec");        ArrSet.add("sudo");          // print CopyOnWriteArraySet        System.out.println("CopyOnWriteArraySet: "                           + ArrSet);          // check using contains() function        if (ArrSet.contains("gfg"))            System.out.println("gfg is "                               + "present in the Set");        else            System.out.println("gfg is "                               + "not present in the Set");          // check using contains() function        if (ArrSet.contains("best"))            System.out.println("best is "                               + "present in the Set");        else            System.out.println("best is "                               + "not present in the Set");    }} |
Output:
CopyOnWriteArraySet: [geeks, gfg, jgec, sudo] gfg is present in the Set best is not present in the Set
