11.What is the purpose of DoublePredicate functional interface?
It represents a predicate (Boolean-valued function) of one double-valued argument.
12.What is the purpose of DoubleSupplier functional interface?
It represents a supplier of double-valued results.
13.What is the purpose of DoubleToIntFunction functional interface?
It represents a function that accepts a double-valued argument and produces an int-valued result.
14.What is the purpose of DoubleToLongFunction functional interface?
It represents a function that accepts a double-valued argument and produces a long-valued result.
15.What is the purpose of DoubleUnaryOperator functional interface?
It represents an operation on a single double-valued operand that produces a double-valued result.
16.What is the purpose of Function<T,R> functional interface?
It represents a function that accepts one argument and produces a result.
17.What is the purpose of IntBinaryOperator functional interface?
It represents an operation upon two int-valued operands and produces an int-valued result.
18.What is the purpose of IntConsumer functional interface?
It represents an operation that accepts a single int-valued argument and returns no result.
19.What is the purpose of IntFunction<R> functional interface?
It represents a function that accepts an int-valued argument and produces a result.
20.What is the purpose of IntPredicate functional interface?
It represents a predicate (Boolean-valued function) of one int-valued argument.
