perl - array of integers using way too much memory?

Question

When I run the following script:

my @arr = [1..5000000];

for($i=0; $i<5000000; $i++) {
        $arr[$i] = $i;
        if($i % 1000000 == 0) {
                    


        

Answer 1

Complete revision of my answer. Looking at what you have in your code, I see some strange things.

my @arr = [1..5000000];

Here, you assign an anonymous array-reference to $arr[0]. This array only holds one value: The array reference. The hidden anonymous array holds the 5 million numbers.

for($i=0; $i<5000000; $i++) {
        $arr[$i] = $i;
        if($i % 1000000 == 0) {
                print "$i\n";
        }
}

Here, you fill the array with 5 million sequential numbers, overwriting the array reference in the declaration.

A much shorter way to do it would be:

my @arr = (1 .. 5_000_000);

Perhaps that will save you some memory.