Stream findFirst() in Java with examples

Stream findFirst() returns an Optional (a container object which may or may not contain a non-null value) describing the first element of this stream, or an empty Optional if the stream is empty. If the stream has no encounter order, then any element may be returned.

Syntax :

Optional<T> findFirst()

Where, Optional is a container object which
may or may not contain a non-null value 
and T is the type of objects and the function
returns an Optional describing the first element 
of this stream, or an empty Optional if the stream is empty.

Exception : If the element selected is null, NullPointerException is thrown.

Note : findAny() is a terminal-short-circuiting operation of Stream interface. This method returns first element satisfying the intermediate operations.

Example 1 : findFirst() function on Stream of Integers.

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code for Stream findFirst()
// which returns an Optional describing
// the first element of this stream, or
// an empty Optional if the stream is empty.
import java.util.*;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
  
        // Creating a List of Integers
        List<Integer> list = Arrays.asList(3, 5, 7, 9, 11);
  
        // Using Stream findFirst()
        Optional<Integer> answer = list.stream().findFirst();
  
        // if the stream is empty, an empty
        // Optional is returned.
        if (answer.isPresent()) {
            System.out.println(answer.get());
        }
        else {
            System.out.println("no value");
        }
    }
}

chevron_right


Output :

3

Example 2 : findFirst() function on Stream of Strings.

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java code for Stream findFirst()
// which returns an Optional describing
// the first element of this stream, or
// an empty Optional if the stream is empty.
import java.util.*;
  
class GFG {
  
    // Driver code
    public static void main(String[] args)
    {
  
        // Creating a List of Strings
        List<String> list = Arrays.asList("GeeksforGeeks", "for",
                                          "GeeksQuiz", "GFG");
  
        // Using Stream findFirst()
        Optional<String> answer = list.stream().findFirst();
  
        // if the stream is empty, an empty
        // Optional is returned.
        if (answer.isPresent()) {
            System.out.println(answer.get());
        }
        else {
            System.out.println("no value");
        }
    }
}

chevron_right


Output :

GeeksforGeeks


My Personal Notes arrow_drop_up

In love with a semicolon because sometimes i miss it so badly)

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.