Java.util.function.BiPredicate interface in Java with Examples

The BiPredicate<T, V> interface was introduced in JDK 8. This interface is packaged in java.util.function package. It operates on two objects and returns a predicate value based on that condition. It is a functional interface and thus can be used in lambda expression also.

public interface BiPredicate<T, V>

Methods:

1. test(): This function evaluates a conditional check on the two objects, and returns a boolean value denoting the outcome.

   boolean test(T obj, V obj1)

2. and(): This function applies the AND operation on the current object and the object received as argument, and returns the newly formed predicate. This method has a default implementation.

   default BiPredicate<T, V> and(BiPredicate<? super T, ? super V> other)

3. negate(): This function returns the inverse of the current predicate i.e reverses the test condition. This method has a default implementation.

   default BiPredicate<T, V> negate() 

4. or(): This function applies the OR operation on the current object and the object received as argument, and returns the newly formed predicate. This method has a default implementation.

   default BiPredicate<T, V> or(BiPredicate<? super T, ? super V> other)

Example:  

Java








// Java example to demonstrate BiPredicate interface    import java.util.function.BiPredicate;    public class BiPredicateDemo {     public static void main(String[] args)     {         // Simple predicate for checking equality         BiPredicate<Integer, String> biPredicate = (n, s) ->         {             if (n == Integer.parseInt(s))                 return true;             return false;         };            System.out.println(biPredicate.test(2, "2"));            // Predicate for checking greater than         BiPredicate<Integer, String> biPredicate1 = (n, s) ->         {             if (n > Integer.parseInt(s))                 return true;             return false;         };            // ANDing the two predicates         BiPredicate<Integer, String> biPredicate2             = biPredicate.and(biPredicate1);         System.out.println(biPredicate2.test(2, "3"));            // ORing the two predicates         biPredicate2 = biPredicate.or(biPredicate1);         System.out.println(biPredicate2.test(3, "2"));            // Negating the predicate         biPredicate2 = biPredicate.negate();         System.out.println(biPredicate2.test(3, "2"));     } }

Output: 

true
false
true
true

 

Reference: https://docs.oracle.com/javase/8/docs/api/java/util/function/BiPredicate.html