The contains() method of Java AbstractCollection is used to check whether an element is present in a Collection or not. It takes the element as a parameter and returns True if the element is present in the collection.
Syntax:
AbstractCollection.contains(Object element)
Parameters: The parameter element is of type Collection. This parameter refers to the element whose occurrence is needed to be checked in the collection.
Return Value: The method returns True if the element is present in the Collection otherwise it returns False.
Below programs illustrate the Java.util.AbstractCollection.contains() method:
Program 1:
// Java code to illustrate boolean contains() import java.util.*;
import java.util.AbstractCollection;
public class AbstractCollectionDemo {
public static void main(String args[])
{
// Creating an empty Collection
AbstractCollection<String>
abs = new LinkedList<String>();
// Use add() method to add
// elements in the collection
abs.add( "Geeks" );
abs.add( "for" );
abs.add( "Geeks" );
abs.add( "10" );
abs.add( "20" );
// Displaying the collection
System.out.println( "Abstract Collection:"
+ abs);
// Check if the collection contains "Hello"
System.out.println( "\nDoes the Collection"
+ " contains 'Hello': "
+ abs.contains( "Hello" ));
// Check if the Collection contains "20"
System.out.println( "Does the collection"
+ " contains '20': "
+ abs.contains( "20" ));
// Check if the Collection contains "Geeks"
System.out.println( "Does the Collection"
+ " contains 'Geeks': "
+ abs.contains( "Geeks" ));
}
} |
Abstract Collection:[Geeks, for, Geeks, 10, 20] Does the Collection contains 'Hello': false Does the collection contains '20': true Does the Collection contains 'Geeks': true
Program 2:
// Java code to illustrate boolean contains() import java.util.*;
import java.util.AbstractCollection;
public class AbstractCollectionDemo {
public static void main(String args[])
{
// Creating an empty Collection
AbstractCollection<String>
abs = new TreeSet<String>();
// Use add() method to add
// elements in the collection
abs.add( "Geeks" );
abs.add( "for" );
abs.add( "Geeks" );
abs.add( "TreeSet" );
abs.add( "20" );
// Displaying the collection
System.out.println( "Abstract Collection:"
+ abs);
// Check if the collection contains "TreeSet"
System.out.println( "\nDoes the Collection "
+ "contains 'TreeSet': "
+ abs.contains( "TreeSet" ));
// Check if the collection contains "Hello"
System.out.println( "\nDoes the Collection"
+ " contains 'Hello': "
+ abs.contains( "Hello" ));
// Check if the Collection contains "20"
System.out.println( "Does the collection"
+ " contains '20': "
+ abs.contains( "20" ));
// Check if the Collection contains "Geeks"
System.out.println( "Does the Collection"
+ " contains 'Geeks': "
+ abs.contains( "Geeks" ));
}
} |
Abstract Collection:[20, Geeks, TreeSet, for] Does the Collection contains 'TreeSet': true Does the Collection contains 'Hello': false Does the collection contains '20': true Does the Collection contains 'Geeks': true