Misconceptions about loops in C

Re:Misconceptions about loops in C by trealira on Friday June 28, 2024 @07:48AM (#40819686)

To be symmetric, the loops should read like this:

  for (i = 0; i < n; i++)
  for (i = n; --i >= 0; )

The second one could also be this:

  for (i = n - 1; i >= 0; i--)

I say this because your backwards loop accesses the inclusive range [0, n] while your forwards range accesses [0, n - 1].

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Re:Misconceptions about loops in C by torstenvl on Friday June 28, 2024 @08:56AM (#40820173)

  for (i = 0; i <= n-1; i++)
  for (i = n-1; i >= 0; i--)

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Re:Misconceptions about loops in C by trealira on Friday June 28, 2024 @09:23AM (#40820391)

Yeah, that way of writing them definitely makes them look more symmetric. You could also do this, though it's a bit less pretty:

  for (i = -1; ++i != n; )
  for (i = n; --i != -1; )

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