IntStream max() in Java with examples

java.util.stream.IntStream in Java 8, deals with primitive ints. It helps to solve the problems like finding maximum value in array, finding minimum value in array, sum of all elements in array, and average of all values in array in a new way. IntStream max() returns an OptionalInt describing the maximum element of this stream, or an empty optional if this stream is empty.

Syntax :

OptionalInt() max()

Where, OptionalInt is a container object which 
may or may not contain a int value.

Example 1 :

// Java code for IntStream max()
import java.util.*;
import java.util.stream.IntStream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {

        // creating a stream
        IntStream stream = IntStream.of(-9, -18, 54, 8, 7, 14, 3);

        // OptionalInt is a container object
        // which may or may not contain a
        // int value.
        OptionalInt obj = stream.max();

        // If a value is present, isPresent() will
        // return true and getAsInt() will
        // return the value
        if (obj.isPresent()) {
            System.out.println(obj.getAsInt());
        }
        else {
            System.out.println("-1");
        }
    }
}

Output :

54

Example 2 :

// Java code for IntStream max()
// to get the maximum value in range
// excluding the last element
import java.util.*;
import java.util.stream.IntStream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {

        // To find maximum in given range
        IntStream stream = IntStream.range(50, 75);

        // storing the maximum value in variable
        // if it is present, else show -1.
        int maximum = stream.max().orElse(-1);

        // displaying the maximum value
        System.out.println(maximum);
    }
}

Output :

74

Example 3 :

// Java code for IntStream max()
// to get the maximum value in range
// excluding the last element
import java.util.*;
import java.util.stream.IntStream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {

        // To find maximum in given range
        IntStream stream = IntStream.range(50, 50);

        // storing the maximum value in variable
        // if it is present, else show -1.
        int maximum = stream.max().orElse(-1);

        // displaying the maximum value
        System.out.println(maximum);
    }
}

Output :

-1