About Question enthuware.ocajp.i.v8.2.1471 :

[Celina]

Why below is wrong

() -> true

I saw in the OCA study book, the parameter can be 0 and below is valid

print(()->true);

[admin]

Did you read the explanation for this option? It explains why this is invalid.
As per the problem statement, you have to pick only such a lambda expression that can be used to invoke a method that accepts a java.util.function.Predicate.

() -> true is a valid lambda expression as such but it cannot implement a Predicate.

[BespawlerC]

Did you read the explanation for this option? It explains why this is invalid.
As per the problem statement, you have to pick only such a lambda expression that can be used to invoke a method that accepts a java.util.function.Predicate.

() -> true is a valid lambda expression as such but it cannot implement a Predicate.

Very nicely explained

[Celina]

Did you read the explanation for this option? It explains why this is invalid.
As per the problem statement, you have to pick only such a lambda expression that can be used to invoke a method that accepts a java.util.function.Predicate.

() -> true is a valid lambda expression as such but it cannot implement a Predicate.

Sorry English is my 2nd lanugage, just misunderstood the question , now I get it. Thanks.

[alfredo.zuloaga]

This is also valid
Predicate predicate = x -> x == null;

[admin]

Yes, it is valid. You may try writing a simple test program to check it out.