Supplier Functional Interfaces

FunctionalInterfaces.java

//Supplier

        Optional<Integer> value = Stream.of(1,2,3,4).reduce(new BinaryOperator<Integer>() {
            @Override
            public Integer apply(Integer x, Integer y) {
                return x + y;
            }
        });

        value.orElseGet(new Supplier<Integer>() {
            @Override
            public Integer get() {
                return -1;
            }
        });


        Optional<Integer> value2 = Stream.of(1,2,3,4).reduce((x, y) -> x + y);

        value2.orElseGet(() -> -1);