1z0-830 Exam Dumps - Java SE 21 Developer Professional

Understanding java.util.function.Predicate<T>

The Predicate interface represents a function thattakes an input and returns a boolean(true or false).

It is often used for filtering operations in functional programming and streams.

Analyzing the Methods:

and(Predicate<? super T> other)→Default method

Combines two predicates usinglogical AND(&&).

java

Predicate startsWithA = s -> s.startsWith("A");

Predicate hasLength3 = s -> s.length() == 3;

Predicate combined = startsWithA.and(hasLength3);

❌isEqual(Object targetRef)→Static method

Not a default method, because it doesnot operate on an instance.

java

Predicate isEqualToHello = Predicate.isEqual("Hello");

negate()→Default method

Negates a predicate (! operator).

java

Predicate notEmpty = s -> !s.isEmpty();

Predicate isEmpty = notEmpty.negate();

❌not(Predicate<? super T> target)→Static method (introduced in Java 11)

Not a default method, since it is static.

or(Predicate<? super T> other)→Default method

Combines two predicates usinglogical OR(||).

❌test(T t)→Abstract method

Not a default method, because every predicatemust implement this method.

Thus, the correct answers are:and(Predicate<? super T> other), negate(), or(Predicate<? super T> other)

References:

Java SE 21 - Predicate Interface

Java SE 21 - Functional Interfaces