The contains() method of Java AbstractSet is used to check whether an element is present in a set or not. It takes the element as a parameter and returns True if the element is present in the set.
Syntax:
public boolean contains(Object element)
Parameters: The parameter element is of type set. This parameter refers to the element whose occurrence is needed to be checked in the set.
Return Value: The method returns a boolean value. It returns True if the element is present in the set otherwise it returns False.
Below programs illustrate the AbstractSet.contains() method:
Program 1:
// Java code to illustrate// AbstractSet.contains()  import java.util.*;  public class GFG {    public static void main(String args[])    {          // Creating an empty set        AbstractSet<String>            abs = new TreeSet<String>();          // Use add() method to add        // elements in the set        abs.add("Geeks");        abs.add("for");        abs.add("Geeks");        abs.add("10");        abs.add("20");          // Displaying the set        System.out.println("AbstractSet: "                           + abs);          // Check if the set contains "Hello"        System.out.println("\nDoes the set"                           + " contains 'Hello': "                           + abs.contains("Hello"));          // Check if the set contains "20"        System.out.println("Does the set"                           + " contains '20': "                           + abs.contains("20"));          // Check if the set contains "Geeks"        System.out.println("Does the set"                           + " contains 'Geeks': "                           + abs.contains("Geeks"));    }} |
Output:
AbstractSet: [10, 20, Geeks, for] Does the set contains 'Hello': false Does the set contains '20': true Does the set contains 'Geeks': true
Program 2:
// Java code to illustrate// AbstractSet.contains()  import java.util.*;  public class GFG {    public static void main(String args[])    {          // Creating an empty set        AbstractSet<Integer>            abs = new TreeSet<Integer>();          // Use add() method to add        // elements in the set        abs.add(10);        abs.add(20);        abs.add(30);        abs.add(40);        abs.add(50);          // Displaying the set        System.out.println("AbstractSet:"                           + abs);          // Check if the set contains 10        System.out.println("\nDoes the set "                           + "contains '10': "                           + abs.contains(10));          // Check if the set contains 50        System.out.println("\nDoes the set"                           + " contains '50': "                           + abs.contains(50));          // Check if the set contains 100        System.out.println("Does the set"                           + " contains '100': "                           + abs.contains(100));    }} |
Output:
AbstractSet:[10, 20, 30, 40, 50] Does the set contains '10': true Does the set contains '50': true Does the set contains '100': false
