What command closes the program?

Question

Java

what to write in the condition to the JButton, which should close the program I
'm just learning to program

Answer 1

2 ways for java:
1) System.exit(status) - closes the application normally, calling shutdown hooks before that.
2) Runtime.getRuntime().halt(status) - closes the program in an extreme way without calling hooks.
The first way is preferable. If it’s not clear what shutdown hooks are, then Google will help.

Answer 2

Then learn how to use Google first!
stackoverflow.com/questions/2670956/how-to-quit-a-...