The contains(E e) method of CopyOnWriteArrayList checks if a given element is present in the list or not. If the element atleast occurs one time, then the function returns true, else it returns false.
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 list.
Return Value: The function returns true if the element is present atleast one time in the list, else it returns false.
Below programs illustrate the above function:
Program 1:
// Java Program to illustrate the CopyOnWriteArrayList // contains() method in Java import java.util.concurrent.CopyOnWriteArrayList;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create object of CopyOnWriteArrayList
CopyOnWriteArrayList<Integer> ArrLis
= new CopyOnWriteArrayList<Integer>();
// Add elements
ArrLis.add( 32 );
ArrLis.add( 67 );
ArrLis.add( 98 );
ArrLis.add( 100 );
// print CopyOnWriteArrayList
System.out.println( "CopyOnWriteArrayList: " + ArrLis);
// check using function
if (ArrLis.contains( 100 ))
System.out.println( "100 is present in the list" );
else
System.out.println( "100 is not present in the list" );
// check using function
if (ArrLis.contains( 20 ))
System.out.println( "20 is present in the list" );
else
System.out.println( "20 is not present in the list" );
}
} |
CopyOnWriteArrayList: [32, 67, 98, 100] 100 is present in the list 20 is not present in the list
Program 2:
// Java Program to illustrate the CopyOnWriteArrayList // contains() method in Java import java.util.concurrent.CopyOnWriteArrayList;
import java.util.*;
public class GFG {
public static void main(String[] args)
{
// create object of CopyOnWriteArrayList
CopyOnWriteArrayList<String> ArrLis
= new CopyOnWriteArrayList<String>();
// Add elements
ArrLis.add( "gopal" );
ArrLis.add( "gfg" );
ArrLis.add( "jgec" );
ArrLis.add( "sudo" );
// print CopyOnWriteArrayList
System.out.println( "CopyOnWriteArrayList: " + ArrLis);
// check using function
if (ArrLis.contains( "gfg" ))
System.out.println( "'gfg' is present in the list" );
else
System.out.println( "'gfg' is not present in the list" );
// check using function
if (ArrLis.contains( "best" ))
System.out.println( "'best' is present in the list" );
else
System.out.println( "'best' is not present in the list" );
}
} |
CopyOnWriteArrayList: [gopal, gfg, jgec, sudo] 'gfg' is present in the list 'best' is not present in the list
Reference: https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CopyOnWriteArrayList.html#contains-E-