What does an IDE add when you open a Java or Kotlin project?
An integrated development environment, or IDE, brings the editor and other project tools into one app. IntelliJ IDEA can help you follow a Java or Kotlin function to where it is defined and use tools for building and debugging the project. Check the project’s required Java version before trying to run it.
How can you inspect a project before allowing it to run?
For an unfamiliar project, choose Preview in Safe Mode if the trust dialog appears. You can read source files there. Safe Mode disables build imports and Git support. For a disposable project you made yourself and trust, the Git Diff Viewer can show the previous and changed lines.
Which parts are free for a commercial app?
The current IntelliJ IDEA desktop download is one unified installer. Core Java and Kotlin development is free for commercial and non-commercial use. Ultimate adds advanced tooling, including deeper framework and database features. Check JetBrains AI eligibility and plan limits separately if you intend to use it.
Would one small change reach the right screen?
On paper, write a fictional Kotlin function that returns a label, then draw two screens that call it. Mark which screen you intend to change before changing the function.
- Trace who uses the codeIf both screens use the same function, write what each would display after your change. Check whether you wanted to affect both.
- Review a proposed editDraw an old and a new line for the intended change. If you open an unfamiliar real project for inspection, stay in Safe Mode and leave builds, connections and AI off.