How to correct indentation in IntelliJ

Code → Reformat Code… (default Ctrl + Alt + L) for the whole file or Code → Auto-Indent Lines (default Ctrl + Alt + I) for the current line or selection. You can customise the settings for how code is auto-formatted under File → Settings → Editor → Code Style. To ensure comments are also indented to the same level as the code, you can simply do as follows: