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
Hello! On page xix of the preface, it says there is a community forum "… for help if your’re stuck on one of the exercises in this book… ...
New
Title: Intuitive Python: docker run… denied error (page 2)
Attempted to run the docker command in both CLI and Powershell
PS C:\Users\r...
New
The book has the same “Problem space/Solution space” diagram on page 18 as is on page 17. The correct Problem/Solution space diagrams ar...
New
I’m running Android Studio “Arctic Fox” 2020.3.1 Patch 2, and I’m embarrassed to admit that I only made it to page 8 before running into ...
New
Hi,
I am getting an error I cannot figure out on my test.
I have what I think is the exact code from the book, other than I changed “us...
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
@parrt
In the context of Chapter 4.3, the grammar Java.g4, meant to parse Java 6 compilation units, no longer passes ANTLR (currently 4....
New
I am using Android Studio Chipmunk | 2021.2.1 Patch 2
Build #AI-212.5712.43.2112.8815526, built on July 10, 2022
Runtime version: 11.0....
New
I got this error when executing the plot files on macOS Ventura 13.0.1 with Python 3.10.8 and matplotlib 3.6.1:
programming_ML/code/03_...
New
Docker-Machine became part of the Docker Toolbox, which was deprecated in 2020, long after Docker Desktop supported Docker Engine nativel...
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
A thread that every forum needs!
Simply post a link to a track on YouTube (or SoundCloud or Vimeo amongst others!) on a separate line an...
New
New
I ended up cancelling my Moonlander order as I think it’s just going to be a bit too bulky for me.
I think the Planck and the Preonic (o...
New
Tailwind CSS is an exciting new CSS framework that allows you to design your site by composing simple utility classes to create complex e...
New
Crystal recently reached version 1. I had been following it for awhile but never got to really learn it. Most languages I picked up out o...
New
Saw this on TikTok of all places! :lol:
Anyone heard of them before?
Lite:
New
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New
I’m able to do the “artistic” part of game-development; character designing/modeling, music, environment modeling, etc.
However, I don’t...
New
A concise guide to MySQL 9 database administration, covering fundamental concepts, techniques, and best practices.
Neil Smyth
MySQL...
New
Categories:
Sub Categories:
Popular Portals
- /elixir
- /rust
- /ruby
- /wasm
- /erlang
- /phoenix
- /keyboards
- /python
- /js
- /rails
- /security
- /go
- /swift
- /vim
- /clojure
- /emacs
- /haskell
- /java
- /svelte
- /onivim
- /typescript
- /kotlin
- /c-plus-plus
- /crystal
- /tailwind
- /react
- /gleam
- /ocaml
- /elm
- /flutter
- /vscode
- /ash
- /opensuse
- /html
- /centos
- /php
- /deepseek
- /zig
- /scala
- /sublime-text
- /lisp
- /textmate
- /react-native
- /debian
- /nixos
- /agda
- /kubuntu
- /arch-linux
- /django
- /deno
- /ubuntu
- /revery
- /nodejs
- /manjaro
- /spring
- /diversity
- /lua
- /julia
- /markdown
- /slackware








