Switch statement with returns -- code correctness

Question

Let s say I have code in C with approximately this structure   switch  something        case 0        return  blah         break       case 1      case 4        return  foo         break       case 2      case 3        return  bar         break       default        return  foobar         break      Now obviously  the breaks are not necessary for the code to run correctly  but it sort of looks like bad practice if I don t put them there to me   What do you think  Is it fine to remove them  Or would you keep them for increased  correctness

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I would remove them  In my book  dead code like that should be considered errors because it makes you do a double-take and ask yourself  How would I ever execute that line

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Interesting  The consensus from most of these answers seems to be that the redundant break statement is unnecessary clutter  On the other hand  I read the break statement in a switch as the  closing  of a case  case blocks that don t end in a break tend to jump out at me as potential fall though bugs   I know that that s not how it is when there s a return instead of a break  but that s how my eyes  read  the case blocks in a switch  so I personally would prefer that each case be paired with a break   But many compilers do complain about the break after a return being superfluous unreachable  and apparently I seem to be in the minority anyway   So get rid of the break following a return   NB  all of this is ignoring whether violating the single entry exit rule is a good idea or not   As far as that goes  I have an opinion that unfortunately changes depending on the circumstances

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Personally I would remove the returns and keep the breaks   I would use the switch statement to assign a value to a variable   Then return that variable after the switch statement   Though this is an arguable point I ve always felt that good design and encapsulation means one way in and one way out   It is much easier to guarantee the logic and you don t accidentally miss cleanup code based on the cyclomatic complexity of your function   One exception   Returning early is okay if a bad parameter is detected at the beginning of a function--before any resources are acquired

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Exit code at one point  That provides better readability to code  Adding return statements  Multiple exits  in between will make debugging difficult

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I personally tend to lose the breaks  Possibly one source of this habit is from programming window procedures for Windows apps   LRESULT WindowProc  HWND hwnd  UINT uMsg  WPARAM wParam  LPARAM lParam        switch  uMsg                case WM SIZE              return sizeHandler                case WM DESTROY              return destroyHandler                               return DefWindowProc hwnd  uMsg  wParam  lParam       I personally find this approach a lot simpler  succinct and flexible than declaring a return variable set by each handler  then returning it at the end  Given this approach  the breaks are redundant and therefore should go - they serve no useful purpose  syntactically or IMO visually  and only bloat the code

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Wouldn t it be better to have an array with  arr 0     blah  arr 1     foo  arr 2     bar    and do return arr something     If it s about the practice in general  you should keep the break statements in the switch  In the event that you don t need return statements in the future  it lessens the chance it will fall through to the next case

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What do you think  Is it fine to remove them  Or would you keep them for increased  correctness     It is fine to remove them  Using return  is exactly the scenario where  break should not be used

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I think the  break s are there for a purpose  It is to keep the  ideology  of programming alive  If we are to just  program  our code without logical coherence perhaps it would be readable to you now  but try tomorrow  Try explaining it to your boss  Try running it on Windows 3030   Bleah  the idea is very simple     Switch   Algorithm       case 1        Call 911     Jump      break     case 2        Call Samantha 28     Forget      break     case 3        Call it a day      break     Return thinkAboutIt 1 return 0   void Samantha 28 int oBed       LONG way from right     SHORT Forget is my job     LONG JMP is for assembly     LONG assembly I work for cops      BOOL allOfTheAbove      int Elligence says anyways thinkAboutIt   break   if we code like this we d be monkeys        Sometimes Programming is supposed to convey the meaning and the essence of the task at hand  It is    there to serve a purpose and to keep it alive  While you are not looking  your program is doing     its thing  Do you trust it     This is how you can       ----------      Break    Please  take a   Break         Just a minor question though  How much coffee have you had while reading the above  I T  Breaks the system sometimes

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Keep the breaks - you re less likely to run into trouble if when you edit the code later if the breaks are already in place   Having said that  it s considered by many  including me  to be bad practice to return from the middle of a function  Ideally a function should have one entry point and one exit point

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I say remove them  If your code is so unreadable that you need to stick breaks in there  to be on the safe side   you should reconsider your coding style     Also I ve always prefered not to mix breaks and returns in the switch statement  but rather stick with one of them

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I would take a different tack entirely   Don t RETURN in the middle of the method function   Instead  just put the return value in a local variable and send it at the end   Personally  I find the following to be more readable   String result        switch  something    case 0    result    blah     break  case 1    result    foo     break     return result

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I d normally write the code without them  IMO  dead code tends to indicate sloppiness and or lack of understanding   Of course  I d also consider something like   char const  rets       blah    foo    bar     return rets something     Edit  even with the edited post  this general idea can work fine   char const  rets        blah    foo    bar    bar    foo     if   unsigned something  lt  5      return rets something  return  foobar     At some point  especially if the input values are sparse  e g   1  100  1000 and 10000   you want a sparse array instead  You can implement that as either a tree or a map reasonably well  though  of course  a switch still works in this case as well

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Remove the break statements  They aren t needed and perhaps some compilers will issue  Unreachable code  warnings

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I would say remove them and define a default  branch

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For  correctness   single entry  single exit blocks are a good idea  At least they were when I did my computer science degree  So I would probably declare a variable  assign to it in the switch and return once at the end of the function

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If you have  lookup  type of code  you could package the switch-case clause in a method by itself   I have a few of these in a  hobby  system I m developing for fun   private int basePerCapitaIncomeRaw int tl        switch  tl            case 0      return 7500          case 1      return 7800          case 2      return 8100          case 3      return 8400          case 4      return 9600          case 5      return 13000          case 6      return 19000          case 7      return 25000          case 8      return 31000          case 9      return 43000          case 10     return 67000          case 11     return 97000          default     return 130000             Yep  That s GURPS space      I agree with others that you should in most cases avoid more than one return in a method  and I do recognize that this one might have been better implemented as an array or something else  I just found switch-case-return to be a pretty easy match to a lookup table with a 1-1 correlation between input and output  like the above thing  role-playing games are full of them  I am sure they exist in other  businesses  as well   D  On the other hand  if the case-clause is more complex  or something happens after the switch-statement  I wouldn t recommend using return in it  but rather set a variable in the switch  end it with a break  and return the value of the variable in the end    On the     third  hand    you can always refactor a switch into its own method    I doubt it will have an effect on performance  and it wouldn t surprise me if modern compilers could even recognize it as something that could be inlined

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Remove them   It s idiomatic to return from case statements  and it s  unreachable code  noise otherwise

[c] Switch statement with returns -- code correctness

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