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
// 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")); }} |
Output:
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
// 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")); }} |
Output:
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
