use strict;

my @data = (1,2,3,4,5,6,7,8,9,10);
my (@temp) = (@data);  # copy array into a temporary array
undef @data;           # wipeout initial array

foreach my $item (@temp) {
  if ($item !~ m/4/) {    # if the element's value is not 4
    push @data, ($item);  # copy it back into the array
  }                       # otherwise do nothing
}