Lambda intermediate operation map

map

​ The elements in the convection can be calculated or converted .

for example ：

​ Print the names of all writers

        List<Author> authors = getAuthors();

        authors
                .stream()
                .map(author -> author.getName())
                .forEach(name->System.out.println(name));

//         Print the names of all writers 
        List<Author> authors = getAuthors();

//        authors.stream()
//                .map(author -> author.getName())
//                .forEach(s -> System.out.println(s));

        authors.stream()
                .map(author -> author.getAge())
                .map(age->age+10)
                .forEach(age-> System.out.println(age));