ok, thank you all for your answers.
I like that way: to mark the element as "undef" in foreach cycle and then delete it throught a grep.
I understood also the lesson of JavaFan: "there is more than one way to do it".
But I'm also searching a way for me. That way must be a little different from the way I usually know (like the construct similar to C/C++), just because from my personal point of view (this is only my vision) I'm using perl just to have shorcuts where other programming languages are using explict constructs.
These shortcuts for me are the funny part of perl.
Thank you for all the answers.