|Do you know where your variables are?|
Because all of the map-based methods construct, copy and later discard, multiple, intermediary lists on their way to constructing the hash.
And the costs of doing large numbers of small memory allocations and deallocations add up; especially if they memory manager has to go to the OS a couple of times to expand the process memory pool.
Using for avoids constructing many of the intermediary lists.
With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.