Predicate.not() Method in Java with Examples

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In order to negate an existing predicate, the Predicate.not() static method added to Java 11. The Predicate class is present in java.util.function package.

Syntax:

negate = Predicate.not( positivePredicate );

Parameters:

Predicate whose negate is required

Return Type: Return type not() method is Predicate.

Approach:

Create one predicate and initialize the conditions to it.
Create another predicate to create negate and assign it with the not() method.

Below is the implementation of the above approach:

Java

// Implementation of Predicate.not() method in Java
import java.util.Arrays;
import java.util.List;
import java.util.function.Predicate;
import java.util.stream.Collectors;
  
public class GFG {
    public static void main(String[] args)
    {
        List<Integer> list
            = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
  
        // creating a predicate for negation
        Predicate<Integer> even = i -> i % 2 == 0;
  
        // creating a predicate object which
        // is negation os supplied predicate
        Predicate<Integer> odd = Predicate.not(even);
  
        // filtering the even number using even predicate
        List<Integer> evenNumbers
            = list.stream().filter(even).collect(
                Collectors.toList());
  
        // filtering the odd number using odd predicate
        List<Integer> oddNumbers
            = list.stream().filter(odd).collect(
                Collectors.toList());
        // Print the Lists
        System.out.println(evenNumbers);
        System.out.println(oddNumbers);
    }
}