array_sum() doesn't "ignore strings if they are not convertible", it converts them to zero. array_product() does the same thing, where the difference between "ignoring" and "converting to zero" is much more obvious.
array_sum() doesn't "ignore strings if they are not convertible", it converts them to zero. array_product() does the same thing, where the difference between "ignoring" and "converting to zero" is much more obvious.