Lambda Expressions and Method References - Java: A Beginner's Guide - page 662

The output is shown here:
In the program, the generic functional interface SomeTest is declared as shown here:
Here, T specifies the type of both parameters for test( ) . This means that it is compatible
with any lambda expression that takes two parameters of the same type and returns a
boolean result.
The SomeTest interface is used to provide a reference to three different types of
lambdas. The first uses type Integer , the second uses type Double , and the third uses type
String . Thus, the same functional interface can be used to refer to the isFactor , isFactorD ,
and isIn lambdas. Only the type argument passed to SomeTest differs.
As a point of interest, the NumericFunc interface shown in the previous section can also
be rewritten as a generic interface. This is an exercise in “ Chapter 14 Self Test,” at the end
of this chapter.
Try This 14-1 Pass a Lambda Expression as an Argument
A lambda expression can be used in any context that provides a target type. The target
contexts used by the preceding examples are assignment and initialization. Another one is
when a lambda expression is passed as an argument. In fact, passing a lambda expression
as an argument is a common use of lambdas. Moreover, it is a very powerful use because it