The size() method of Java AbstractCollection is used to get the size of the Collection or the number of elements present in the Collection.
Syntax:
AbstractCollection.size()
Parameters: The method does not take any parameter.
Return Value: The method returns the size or the number of elements present in the collection.
Below programs illustrates the use of AbstractCollection.size() method:
Program 1:
Java
// Java code to illustrate size() 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 into the Collection
abs.add( "Welcome" );
abs.add( "To" );
abs.add( "Geeks" );
abs.add( "4" );
abs.add( "Geeks" );
abs.add( "TreeSet" );
// Displaying the Collection
System.out.println( "Collection: " + abs);
// Displaying the size of the collection
System.out.println( "The size of the Collection is: "
+ abs.size());
}
} |
Output:
Collection: [4, Geeks, To, TreeSet, Welcome] The size of the Collection is: 5
Program 2:
Java
// Java code to illustrate size() 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>();
// Using 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( "Collection:" + abs);
// Displaying the size of the Collection
System.out.println( "The size of the Collection is: "
+ abs.size());
}
} |
Output:
Collection:[Geeks, for, Geeks, 10, 20] The size of the Collection is: 5