dtonhofer
Functional Programming in Java, Second Edition: p. 55 "Compare.java" can be further simplified
On page 55, we see Compare.java
final Function<Person, String> byName = person -> person.getName();
people.stream()
.sorted(comparing(byName));
However, this can be further simplified to:
people.stream()
.sorted(comparing(Person::getName));
On the same page, more from Compare.java:
final Function<Person, Integer> byAge = person -> person.getAge();
final Function<Person, String> byTheirName = person -> person.getName();
printPeople("Sorted in ascending order by age, then name: ",
people.stream()
.sorted(comparing(byAge).thenComparing(byTheirName))
.collect(toList());
which can be simplified similarly to:
printPeople("Sorted in ascending order by age, then name: ",
people.stream()
sorted(comparing(Person::getAge).thenComparing(Person::getName))
.collect(toList());
but which would be even better by separating the list generation and output tasks:
List<Person> asc =
people.stream()
.sorted(comparing(Person::getAge).thenComparing(Person::getName))
.collect(toList());
printPeople("Sorted in ascending order by age, then name: ", asc);
…all according to the JavaDoc for Comparator:
P.S.
Would it be clearer to explicitly write the class from which comparing() comes instead of assuming it has been imported statically? Like this:
people.stream()
.sorted(Comparator.comparing(Person::getName));
instaed of
people.stream()
.sorted(comparing(Person::getName));
Note that the collect()call
people.stream()
.sorted(comparing(byAge).thenComparing(byTheirName))
.collect(toList()));
…also assume a statically imported toList(). On the other hand, compare/fpij/OlderThan20.java on page 58 is explicit:
List<Person> olderThan20 =
people.stream()
.filter(person -> person.getAge() > 20)
.collect(Collectors.toList());
Popular Pragmatic Bookshelf topics
Python Testing With Pytest - Chapter 2, warnings for “unregistered custom marks”
While running the smoke tests in Chapter 2, I get these...
New
your book suggests to use Image.toByteData() to convert image to bytes, however I get the following error: "the getter ‘toByteData’ isn’t...
New
The following is cross-posted from the original Ray Tracer Challenge forum, from a post by garfieldnate. I’m cross-posting it so that the...
New
Hi everyone!
There is an error on the page 71 in the book “Programming machine learning from coding to depp learning” P. Perrotta. You c...
New
Hi @Margaret ,
On page VII the book tells us the example and snippets will be all using Elixir version 1.11
But on page 3 almost the en...
New
Hi! I know not the intentions behind this narrative when called, on page XI:
mount() |> handle_event() |> render()
but the correc...
New
Is there any place where we can discuss the solutions to some of the exercises? I can figure most of them out, but am having trouble with...
New
Hi all,
currently I wonder how the Tailwind colours work (or don’t work).
For example, in app/views/layouts/application.html.erb I have...
New
Title: Agile Web Development with Rails 7: (page 70)
I am running windows 11 pro with rails 7.0.3 and ruby 3.1.2p20 (2022-04-12 revision...
New
I’ve got to the end of Ch. 11, and the app runs, with all tabs displaying what they should – at first. After switching around between St...
New
Other popular topics
Reading something? Working on something? Planning something? Changing jobs even!?
If you’re up for sharing, please let us know what you’...
New
Free and open source software is the default choice for the technologies that run our world, and it’s built and maintained by people like...
New
Learn from the award-winning programming series that inspired the Elixir language, and go on a step-by-step journey through the most impo...
New
From finance to artificial intelligence, genetic algorithms are a powerful tool with a wide array of applications. But you don't need an ...
New
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
I am asking for any distro that only has the bare-bones to be able to get a shell in the server and then just install the packages as we ...
New
Author Spotlight
Dmitry Zinoviev
@aqsaqal
Today we’re putting our spotlight on Dmitry Zinoviev, author of Data Science Essentials in ...
New
I am trying to crate a game for the Nintendo switch, I wanted to use Java as I am comfortable with that programming language. Can you use...
New
Author Spotlight
Mike Riley
@mriley
This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
Hair Salon Games for Girls Fun
Girls Hair Saloon game is mainly developed for kids. This game allows users to select virtual avatars to ...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /wasm
- /ruby
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /java
- /emacs
- /haskell
- /svelte
- /onivim
- /typescript
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /flutter
- /elm
- /vscode
- /ash
- /html
- /opensuse
- /zig
- /deepseek
- /centos
- /php
- /scala
- /react-native
- /lisp
- /sublime-text
- /textmate
- /nixos
- /debian
- /agda
- /deno
- /django
- /kubuntu
- /arch-linux
- /nodejs
- /spring
- /ubuntu
- /revery
- /manjaro
- /lua
- /diversity
- /julia
- /markdown
- /quarkus









