How and in what situation Ruby pack() methods need to use with directives?

[arupface]

Could you please tell me how the below directives works with Ruby array pack() method. As the document not gives piece of code to describe what to use , when?

n,v,U,w,L!<,S!< I!<

thanks

[Taywin]

Do you know big/little endian? It is about using template from the most/least significant bits. If you don't know, you may not need to do anything with it. Also, pack() function is not really common for regular programming, so you could ignore it.