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()); } } |
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()); } } |
Collection:[Geeks, for, Geeks, 10, 20] The size of the Collection is: 5