How do I perform an operation on a series of integers?

    @results = map { my_func($_) } @array;

For example:

    @triple = map { 3 * $_ } @single;

To call a function on each element of an array, but ignore the results:

    foreach $iterator (@array) {
        &my_func($iterator);
    }

To call a function on each integer in a (small) range, you can use:

    @results = map { &my_func($_) } (5 .. 25);

but you should be aware that the .. operator creates an array of all integers in the range. This can take a lot of memory for large ranges. Instead use:

    @results = ();
    for ($i=5; $i < 500_005; $i++) {
        push(@results, &my_func($i));
    }