IntStream filter() in Java with examples

IntStream filter(IntPredicate predicate) returns a stream consisting of the elements of this stream that match the given predicate. This is an intermediate operation. These operations are always lazy i.e, executing an intermediate operation such as filter() does not actually perform any filtering, but instead creates a new stream that, when traversed, contains the elements of the initial stream that match the given predicate.

Syntax :

IntStream filter(IntPredicate predicate)

Where, IntStream is a sequence of primitive int-valued elements.
IntPredicate represents a predicate (boolean-valued function) 
of one int-valued argument and the function returns the new stream.

Example 1 : filter() method on IntStream.

// Java code for IntStream filter
// (IntPredicate predicate) to get a stream
// consisting of the elements of this
// stream that match the given predicate.
import java.util.*;
import java.util.stream.IntStream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {
        // Creating an IntStream
        IntStream stream = IntStream.of(3, 5, 6, 8, 9);

        // Using IntStream filter(IntPredicate predicate)
        // to get a stream consisting of the
        // elements that gives remainder 2 when
        // divided by 3
        stream.filter(num -> num % 3 == 2)
            .forEach(System.out::println);
    }
}

Output :

5
8

Example 2 : filter() method on IntStream.

// Java code for IntStream filter
// (IntPredicate predicate) to get a stream
// consisting of the elements of this
// stream that match the given predicate.
import java.util.*;
import java.util.stream.IntStream;

class GFG {

    // Driver code
    public static void main(String[] args)
    {
        // Creating an IntStream
        IntStream stream = IntStream.of(-2, -1, 0, 1, 2);

        // Using IntStream filter(IntPredicate predicate)
        // to get a stream consisting of the
        // elements that are greater than 0
        stream.filter(num -> num > 0)
            .forEach(System.out::println);
    }
}

Output :

1
2