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SortedSet first() method in Java

The first() method of SortedSet interface in Java is used toReturns the first i.e., the lowest element currently in this set.
Syntax

E first()

Where, E is the type of element maintained by this Set.
Parameters: This function does not accepts any parameter.
Return Value: It returns the first or the lowest element currently in the set.
Exceptions: It throws NoSuchElementException, if the set is empty.
Below programs illustrate the above method:
Program 1






// A Java program to demonstrate
// working of SortedSet
 
import java.util.SortedSet;
import java.util.TreeSet;
 
public class Main {
    public static void main(String[] args)
    {
        // Create a TreeSet and inserting elements
        SortedSet<Integer> s = new TreeSet<>();
 
        // Adding Element to SortedSet
        s.add(1);
        s.add(5);
        s.add(2);
        s.add(3);
        s.add(9);
 
        // Returning the lowest element from set
        System.out.print("Lowest element in set is : "
                         + s.first());
    }
}

Output: 
Lowest element in set is : 1

 

Program 2






// Program to illustrate the first()
// method of SortedSet interface
 
import java.util.SortedSet;
import java.util.TreeSet;
 
public class GFG {
    public static void main(String args[])
    {
        // Create an empty SortedSet
        SortedSet<Integer> s = new TreeSet<>();
 
        // Trying to access element from
        // empty set
        try {
            s.first();
        }
        catch (Exception e) {
            // throws NoSuchElementException
            System.out.println("Exception: " + e);
        }
    }
}

Output: 
Exception: java.util.NoSuchElementException

 

Reference: https://docs.oracle.com/javase/10/docs/api/java/util/SortedSet.html#first()
 


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