How to create and run Java programs in IntelliJ IDEA?

The steps to create and run a Java program in IntelliJ IDEA are as follows:

1. Open IntelliJ IDEA and create a new Java project by selecting File -> New -> Project, then choose Java and click Next. Enter the project name and location in the following dialog box, then click Finish.
2. Create a new Java class by right-clicking on the src folder in the project, selecting New -> Java Class. Enter the class name in the pop-up dialog box and click OK.
3. Write Java code: Write your Java code in a newly created Java class.
4. To run a Java program: click on ‘Run’ in IDEA and select ‘YourClassName.main()’ to run your Java program. Alternatively, you can directly click on the green triangle button in the top right corner of IDEA to run the program.
5. Check the program output: View the program output in the bottom output window of IDEA.

By following the above steps, you can create and run Java programs in IntelliJ IDEA.