my @array = map { STMT* EXPR } LIST;

##</code><code>##

my @array;
for (LIST) {
   STMT*
   push @array, EXPR;
}

##</code><code>##

my @array = grep EXPR, LIST;

##</code><code>##

my @array;
for (LIST) {
   if (EXPR) {
      push @array, $_;
   }
}