Please ensure that: Your code is properly formatted as code block - see the sidebar (About on mobile) for instructions You include any and all error messages in full - best also formatted as code block You ask clear questions You demonstrate effort in solving your question/problem - plain posting your assignments is forbidden (and such posts will be removed) as is asking for or giving solutions. If any of the above points is not met, your post can and will be removed without further warning. Code is to be formatted as code block (old reddit/markdown editor: empty line before the code, each code line indented by 4 spaces, new reddit: https://imgur.com/a/fgoFFis ) or linked via an external code hoster, like pastebin.com, github gist, github, bitbucket, gitlab, etc. Please, do not use triple backticks (```) as they will only render properly on new reddit, not on old reddit. Code blocks look like this: public class HelloWorld { public static void main(String[] args) { System.out.println("Hello World!"); } } You do not need to repost unless your post has been removed by a moderator. Just use the edit function of reddit to make sure your post complies with the above. If your post has remained in violation of these rules for a prolonged period of time (at least an hour), a moderator may remove it at their discretion. In this case, they will comment with an explanation on why it has been removed, and you will be required to resubmit the entire post following the proper procedures. To potential helpers Please, do not help if any of the above points are not met, rather report the post. We are trying to improve the quality of posts here. In helping people who can't be bothered to comply with the above points, you are doing the community a disservice. I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns. More on reddit.com

You may need to open the module settings to make sure the Java SDK and versions are set right. Make sure it is imported as a maven project- IntelliJ should automatically mark src/main/Java, src/test/java, etc as code and resources root but it doesn’t look like it is in your case. You can right click on folders in the project view and choose mark folder as > choose the appropriate option. More on reddit.com

It seems that you are looking for resources for learning Java. In our sidebar ("About" on mobile), we have a section "Free Tutorials" where we list the most commonly recommended courses. To make it easier for you, the recommendations are posted right here: MOOC Java Programming from the University of Helsinki Java for Complete Beginners accompanying site CaveOfProgramming Derek Banas' Java Playlist accompanying site NewThinkTank Hyperskill is a fairly new resource from Jetbrains (the maker of IntelliJ) Also, don't forget to look at: The official Documentation The official Java Tutorials Our community resources thread If you are looking for learning resources for Data Structures and Algorithms, look into: "Algorithms" by Robert Sedgewick and Kevin Wayne - Princeton University Coursera course: Part I Part II Coursebook Algorithms 4th Edition Your post remains visible. There is nothing you need to do. I am a bot and this message was triggered by keywords like "learn", "learning", "course" in the title of your post. I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns. More on reddit.com

Please share a screenshot of the entire IntelliJ window. Make sure the project view is open and we can see the files on the top level folder. Also make sure the Maven tool window is open (right hand side) If there is no such tool window, make sure the Maven plugin is enabled in the settings. More on reddit.com