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@davidbisset Nope assigning it to null doesn't help.

However, if your array is more than just allocated but has actual values in each element. Say a long string... unsetting it DOES reduce the memory usage.

I modified the example to add a step which assigns each element:

str_repeat("abcdefg", 100);

And memory use went up of course. But then after unsetting each element it does drop the memory back down. So unsetting array elements is worth it.

@syntaxseed @davidbisset I'm guessing assigning to null still keeps the reference count for the array item > 0, so it won't get cleared by garbage collection. And, as you found, explicitly unsetting it does. Tideways has an explanation for memory + variables: https://tideways.com/profiler/blog/what-is-garbage-collection-in-php-and-how-do-you-make-the-most-of-it

@omerida @syntaxseed Like I said, learned something. And thanks for the extra info too.