Over 570 examples with explanations: Java and SQL. Over 320 of them free, and code runs right in the app with the output shown underneath.
A reference of everyday Java, from strings and collections to threading and design patterns. Every example comes with an explanation, and most of them run.
• 22 sections: simple types, arrays and collections, classes, interfaces and generics, functions and lambdas, files, serialization, exceptions, regular expressions, threading, databases, patterns.
• Run in the app: the example really executes and the output appears under the code. Needs an internet connection.
• What changed in new versions: 8 sections from Java 9 to 21, with "before" and "after" code side by side.
• Keyword and function reference: 160 articles, fully open with no daily counter.
• SQL alongside: over 200 queries against a live practice database - JOIN, GROUP BY, subqueries, data types.
• Edit examples and add your own - they stay in the app and are always at hand.
• Search runs over the code itself, not just the titles: remember a fragment and you will find the example.
• Everything except running works offline. No account needed.
WHAT THE FREE VERSION INCLUDES
12 runs and 12 edits a day - the counter resets every morning. The keyword reference is open without limits. Up to 5 examples of your own. Copying in the free app is blocked after five attempts.
The full version opens every example, removes the daily limits and raises running to 30 launches a day. One purchase, no subscription.
Made by a developer for developers. In development since 2015.
This app gives a paster a fighting chance at learning code.
Developer Response
Thanks for your feedback 🤝
Broken Link
Yoyohenriques
Would be five stars but the link to the playground for using the code is broken.
Developer Response
Thanks for flagging it. You don't need the link to try the code: the Run button runs the example right in the app and shows the output. If a link in a particular example is broken, tap Discuss under it and I'll fix it.
Love it!
Generic Earthling
This is by far the best set of java examples I have ever found! It’s a dream come true for me as a new developer. It is so simple to use. There is no fancy graphics blocking its readability. It has a nice dark mode and you can adjust the font size of the code. The code is also color coded so it’s easy to read. Under the code is a link to post comments or discuss the code or topic. The link takes you to the website forum. I gladly paid the 3 sets of .99 cents for the full version. (Why is it set up like that?) NOTE TO DEVELOPER: 1. Please add a link in the settings area for users to click on to write a review for this app. I saw it when I purchased it, but couldn’t go back to it. 2. The payment area was confusing to me. 3. Add a link to your website in the settings area and add your name to it. You deserve some recognition!
• Run code right in the app - Java executes and the output is shown under the example.
• A "What changed in new versions" section: what arrived from Java 9 to 21.
• The keyword and function reference is now a section of its own, with search.
• Your own examples: add your code and keep it in the app.
Version 4.06
The developer, Fedor Obraztsov, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
