I loved the environment they provided to write code and queries. It gives suggestions for each keyword or predefined methods as well.

There is a lot to do on CodinGame, and it is a great site for programmers of all skill levels to go and learn and practice. You can work on programming puzzles that are in varying skill levels from easy to very hard. If you need a bigger challenge there are bot programming competitions where you write AI bots to play games against the bots of other programmers. If you want something quick you can to 5 minute coding battle in Clash of Code. These are my favorites, and there is more than that to do on the site. The browser based code editor on CodinGame is perhaps the best I've seen on line, but if you don't like that CodinGame has a Chrome plugin that allows you to sync with your local file system which allows you to use your favorite IDE. CodinGame supports a large list of programming languages, from the very popular to the not so popular. If you want to learn a new programming language this a great place to practice using it. CodinGame has a very active community of programmers. You can always find help in the Forums or using the built in chat feature. It really is a very active site.

I like better the bot programming challenges