interfacce note(voli)

index

Predicate<T>

Function<T, R>

Supplier<T>

Consumer<T>

Comparator

funzione a valori booleani a un solo argomento generico T (in un certo senso controlla qualcosa)

Modifier and Type	Method
`default Predicate<T>`	`and(Predicate<? super T> other)` Returns a composed predicate that represents a short-circuiting logical AND of this predicate and another
`static <T> Predicate<T>`	`isEqual(Object targerRef)` Returns a predicate that tests if two arguments are equal according to `Object.equals(Object, Object)`
`default Predicate<T>`	`negate()` Returns a predicate that represents the logical negation of this predicate
`default Predicate<T>`	`or(Predicate<? super T> other)` Returns a composed predicate that represents a short-circuiting logical OR of this predicate and another
`boolean`	`test(T t)` Evaluates this predicate on the given argument

Predicate<String> predicate = s-> s.length() > 0;
 
Predicate<String> predicate2 = s-> s.startsWith("f")

esiste anche BiPredicate, con due valori in input.

BiPredicate<String, Integer> bp2_4_3 = (s, i) -> s.length() == i;

argomenti T d’ingresso e R di ritorno entrambi generici

Modifier and Type	Method
`default <V> Function<T,V>`	`andThen(Function<? supper R,? extends V> after)` Returns a composed function that first applies this function to its input, and then applies the `after` function to the result.
`R`	`apply(T t)` Applies this function to the given argument
`default <V> Function<V,R>`	`compose(Function<? super V,? extends T> before` Returns a composed function that first applies the `before` function to its input, and then applies this function to the result.
`static <T> Function<T,T>`	`identify()` Returns a function that always returns its input arguments

Function<String, Integer> toInteger = Integer::valueOf;

funzione senza argomenti in input

Supplier<String> stringSupplier = () -> "ciao";
 
Supplier<Person> personSupplier = Person::new;
personSupplier.get(); // new Person();

argomento di tipo generico T e nessun tipo di ritorno

Consumer<Person> greeter1 = p-> System.out.println("hello"+p);

notes-ig