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Asked: 2026-05-10T15:55:49+00:00

When reviewing, I sometimes encounter this kind of loop: i = begin while (

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When reviewing, I sometimes encounter this kind of loop:

i = begin while ( i != end ) {        // ... do stuff    if ( i == end-1 (the one-but-last element) ) {       ... do other stuff    }    increment i }

Then I ask the question: would you write this?

i = begin mid = ( end - begin ) / 2 // (the middle element) while ( i != end ) {        // ... do stuff    if ( i > mid ) {       ... do other stuff    }    increment i }

In my opinion, this beats the intention of writing a loop: you loop because there is something common to be done for each of the elements. Using this construct, for some of the elements you do something different. So, I conclude, you need a separate loop for those elements:

i = begin mid = ( end - begin ) / 2 //(the middle element) while ( i != mid ) {        // ... do stuff    increment i }  while ( i != end ) {    // ... do stuff    // ... do other stuff    increment i }

Now I even saw a question on SO on how to write the if-clause in a nice way… And I got sad: something isn’t right here.

Am I wrong? If so, what’s so good about cluttering the loop body with special cases, which you are aware of upfront, at coding time?

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1 Answer

  1. @xtofl,

    I agree with your concern.

    Million times I encountered similar problem.

    Either developer adds special handling for first or for last element.

    In most cases it is worth to just loop from startIdx + 1 or to endIdx – 1 element or even split one long loop into multiple shorter loops.

    In a very rare cases it’s not possible to split loop.

    In my opinion uncommon things should be handled outside of the loop whenever possible.

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