actually whenever a program runs for the first time then static scope is runned once so it's used for initiallization. However if the program runs again then this static block will be skipped so yeah it good to use this.

Help us help you. Tell us which language you're having this problem with. Also, post your code as a spoiler, otherwise we can't very well tell what's going wrong where.

Closing.

Could you please show the code you have written. The error might be caused by which array you have returned.