Backend>Questions

Java equals() selection

sona11

sona11

Java equals() selection

In Java, if I try to do.equals() on a null string, a null pointer error is issued. I’m wondering whether I can perform the following if I’m attempting to compare if a string is equal to a constant string:
MY CONSTANT STRING.equals(aStringVariable)
I’m sure it’ll work, but is this simply extremely bad code?
This is a common Java idiom known colloquially as a Yoda condition. Personally, I prefer to handle the null situation directly, but the Yoda method is widely used, and any competent Java programmer should quickly grasp what is going on. How should I proceed?

3 comments
/java
4 1150 3

Most Liked

faust

faust

I think that it is important to discuss with your team how the majority feels about this kind of situation and create a guideline for the project.

Anyway, I personally prefer to use Enums instead of this kind of constant.

1
Post #3
finner

finner

Hi @sona11,
If you are using Java8 (or ablove) you can use Optional - for example:

boolean eq = Optional.ofNullable(aStringVariable)
            .map(s -> s.equals(MY_CONSTANT_STRING))
            .orElse(false);

And when the aStringValue is null there will no NullPointerException

I hope I understood the question correctly, does that help?

1
Post #4
sona11

sona11

Thanks you and yes it does help.

1
Post #5

Where Next?

View thread on forum
java
Home Backend>Questions
/java
4 1150 3
Last post

Popular Backend topics Top

AstonJ
Backend>Questions

Erlang's not installing on macOS Big Sur "You are natively building Erlang/OTP for a later version of MacOSX than current version"
Just done a fresh install of macOS Big Sur and on installing Erlang I am getting: asdf install erlang 23.1.2 Configure failed. checking ...
#macos/erlang#big-sur#asdf
10 6212 8
New
JimmyCarterSon
Backend>Questions

Troubleshooting Code: (KeyError) key :changeset not found
I am following this tutorial . I have followed carefully correcting errors as I go. The app allows you to create a blog post and add comm...
/elixir#debugging#troubleshooting
9 2553 3
New
Fl4m3Ph03n1x
Backend>Questions

Ecto multiple streams in 1 transaction
Background PS: the following situation describes an hypothetical scenario, where I own a company that sells things to customers. I have ...
/elixir#backend
5 1586 2
New
AstonJ
Backend>Questions

Rails db:create error - PG::ConnectionBad: connection to server on socket "/tmp/.s.PGSQL.5432" failed: FATAL: database "_development" does not exist
If when trying to create (or recreate) your dev db with rails db:create you are getting: PG::ConnectionBad: connection to server on soc...
/rails#troubleshooting
3 2357 0
New
sona11
Backend>Questions

Java equals() selection
In Java, if I try to do.equals() on a null string, a null pointer error is issued. I’m wondering whether I can perform the following if I...
/java
4 1150 3
New
sona11
Backend>Questions

Fibonacci series using java
I wrote this code to calculate Fibonacci numbers by specifying the size. The results are correct, however the one thing that concerns me ...
/java
4 1372 1
New
Fl4m3Ph03n1x
Backend>Questions

Cannot compile ssl_verify_fun in Windows 11 for Elixir
Background I have a phoenix application in Windows 11. Unfortunately for me, I cannot compile the application because of a dependency err...
/elixir/phoenix
4 1486 2
New
pillaiindu
Backend>Questions

What is the difference between using `:references` and `:belongs_to` in a generate command in Rails?
What is the difference between using :references and :belongs_to in the following command? bin/rails generate scaffold LineItem product:...
/ruby/rails
5 824 2
New
AstonJ
Backend>Questions

Psql: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: No such file or directory
If you’re getting errors like this: psql: error: connection to server on socket “/tmp/.s.PGSQL.5432” failed: No such file or directory ...
#macos/rails/postgresql
1 5553 1
New
Fl4m3Ph03n1x
Backend>Questions

Are there any text-to-speech ai tools available using elixir?
Background As I often do, I read books to learn and improve myself. I also enjoy teaching and helping others when I can, so this is somet...
/elixir
6 588 3
New

Other popular topics Top

PragmaticBookshelf
General Dev>Learning Resources

A Common-Sense Guide to Data Structures and Algorithms, Second Edition
Algorithms and data structures are much more than abstract concepts. Mastering them enables you to write code that runs faster and more e...
pragprog.com
#pragprog/python/ruby#published-book/book-a-common-sense-guide-to-data-structures-and-algorithms-second-edition#math#algorithms/js
19 6022 5
New
PragmaticBookshelf
Backend>Learning Resources

Programming Machine Learning
Machine learning can be intimidating, with its reliance on math and algorithms that most programmers don't encounter in their regular wor...
pragprog.com
#pragprog#ai/python#published-book/book-programming-machine-learning#math#algorithms
6 5350 3
New
PragmaticBookshelf
Backend>Learning Resources

Testing Elixir
Write Elixir tests that you can be proud of. Dive into Elixir’s test philosophy and gain mastery over the terminology and concepts that u...
pragprog.com
#pragprog/elixir#published-book/book-testing-elixir
33 5004 8
New
ohm
Science/Tech>Tech Chat

Games! Which do you play?
Which, if any, games do you play? On what platform? I just bought (and completed) Minecraft Dungeons for my Nintendo Switch. Other than ...
#games
246 6097 101
New
AstonJ
General Dev>Hardware

GMK Serika Keycaps - Serika 2 available to order now!
I have seen the keycaps I want - they are due for a group-buy this week but won’t be delivered until October next year!!! :rofl: The Ser...
/keyboards#keycaps#mechanical-keyboards
9 5097 7
New
PragmaticBookshelf
Frontend>Learning Resources

Modern CSS with Tailwind
Tailwind CSS is an exciting new CSS framework that allows you to design your site by composing simple utility classes to create complex e...
pragprog.com
#pragprog/tailwind#published-book/book-modern-css-with-tailwind
12 5813 4
New
AstonJ
Science/Tech>Health & Diet

David Sinclair's new Lifespan podcast
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...
#health#podcasts#bio-hackers#david-sinclair
87 6790 49
New
AstonJ
General Dev>Code Editors

Doom-Emacs: Can't find emacs in your PATH
If you get Can't find emacs in your PATH when trying to install Doom Emacs on your Mac you… just… need to install Emacs first! :lol: bre...
#macos/emacs#doom-emacs
4 5837 0
New
PragmaticBookshelf
General Dev>Learning Resources

A Common-Sense Guide to Data Structures and Algorithms in Python, Volume 1
Big O Notation can make your code faster by orders of magnitude. Get the hands-on info you need to master data structures and algorithms ...
pragprog.com
#pragprog/python#published-book/book-a-common-sense-guide-to-data-structures-and-algorithms-in-python-volume-1
24 5988 11
New
AstonJ
Backend>Questions

Psql: error: connection to server on socket "/tmp/.s.PGSQL.5432" failed: No such file or directory
If you’re getting errors like this: psql: error: connection to server on socket “/tmp/.s.PGSQL.5432” failed: No such file or directory ...
#macos/rails/postgresql
1 5553 1
New
Back to top

Sponsor Spotlight

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Latest in Java

Java Portal ❯

Backend>Questions

Backend Questions ❯

Latest on Devtalk

Devtalk ❯

We ❤️ helpful members!

We reward our most helpful members via our MOTM scheme - by giving away a whopping 25 books per year!

Member of the Month

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

Categories:

Sub Categories:

Popular Portals

Devtalk Sponsors

Pragmatic Bookshelf

Practical resources that improve the lives of professional developers.

Erlang Solutions

We build trusted fault-tolerant systems that scale to billions of users.

Honeybadger

Real-time error tracking, performance insights, and observability for devs.

EEF

Supporting innovation across the BEAM ecosystem.

coders51

We build reliable cloud platforms for business-critical systems.

Manning Publications

Develop your skills with books, videos, and courses.

AppSignal

Catch errors, track performance, monitor hosts and more.

WyeWorks

Enabling companies to succeed by building software people love.

Pragmatic Studio

Courses that move you from confusion to "Aha, now I get it!"

Linux New Media

Publishing Linux Magazine, ADMIN, and MakerSpace for 25+ years.

View all our sponsors ❯

We're in Beta

About us Mission Statement See our Roadmap