An alternative to Do While loops?

wyrmmage

Moderator

Posts: 370
Joined: 2006.08

Post: #1

Aug 11, 2008 — 02:41 PM

Hello again everyone

I haven't posted in awhile, but I've been lurking...

I've run across some (C++) code that I have once before a while loop begins executing and then again at the end of the loop. The solution seems to be to use a do...while loop, but I hate do while loops. In my opinion, they look horrible and are much harder to read than normal while loops.

Any ideas on a different solution that is cleaner and better looking? Perhaps I'm just being stubborn, but I really don't like do while loops

Here's the code that I noticed this in:

Code:

frame tempFrame;

tempFrame.texture = -1;

std::string tempString = "";

std::string dataLine;

getline(animReadFile, dataLine);

char* stringPoint;

   while(dataLine.size() > 0)

   {

      for(stringPoint=(char*)dataLine.c_string(); *stringPoint!='\0'; stringPoint++)

      {

      //some code

      }

   //more code

   tempFrame.texture = -1;

   tempString = "";

   getline(animReadFile, dataLine);

   }

Thanks

-wyrmmage

Worlds at War (Current Project) - http://www.awkward-games.com/forum/

green_ghost

Member

Posts: 35
Joined: 2008.06

Post: #2

Aug 11, 2008 — 08:11 PM

Here's a way, .... not saying it is any cleaner

.... but less code, and no do-while.

Code:

frame tempFrame;

tempFrame.texture = -1;

std::string tempString = "";

std::string dataLine;

char* stringPoint;

   while ( 1 ) {

      getline(animReadFile, dataLine);

      if ( dataLine.size() <= 0 ) {

     break;

      }

      for(stringPoint=(char*)dataLine.c_string(); *stringPoint!='\0'; stringPoint++)

      {

      //some code

      }

     //more code

     tempFrame.texture = -1;

     tempString = "";

   }

wyrmmage

Moderator

Posts: 370
Joined: 2006.08

Post: #3

Aug 11, 2008 — 09:23 PM

Well, that is definitely an alternate solution

Still, as you said, it's not exactly a clean solution...but I still like it better than do while loops

Any other suggestions?

Thanks,
-wyrmmage

Worlds at War (Current Project) - http://www.awkward-games.com/forum/

ThemsAllTook

Moderator

Posts: 1,552
Joined: 2003.10

Post: #4

Aug 12, 2008 — 06:39 AM

wyrmmage Wrote:Any other suggestions?

Learning not to hate do while loops would be the best solution. They're part of the core language syntax, so why avoid them arbitrarily?

bronxbomber92

Member

Posts: 312
Joined: 2006.10

Post: #5

Aug 12, 2008 — 08:12 AM

Plus, those aren't do-while loops.. (unless I'm misunderstanding what you're saying?)

But yeah, why avoid them? Your code looks more messy because of the indenting than the while loop.

dsMediaLabs
Cocoa Touch Games

wyrmmage

Moderator

Posts: 370
Joined: 2006.08

Post: #6

Aug 12, 2008 — 12:52 PM

I know they aren't do while loops; I was just saying that I was going to convert my code to use do while loops to reduce code duplication.

Personally, I like my style of indentation better, but each to their own

I guess I'll just learn to love do while loops, then

Thanks everyone

-wyrmmage

Worlds at War (Current Project) - http://www.awkward-games.com/forum/

green_ghost

Member

Posts: 35
Joined: 2008.06

Post: #7

Aug 12, 2008 — 05:08 PM

Even with a do-while, you are still going to have to (or should) check after the first read, and then again at the bottom of the loop

Code:

1st read

if ( dataLine.size() > 0 ) {

     do {

           // some code

           2nd read

     } while ( dataLine.size() > 0 )

} // endif

one_each

Nibbie

Posts: 1
Joined: 2008.12

Post: #8

Dec 18, 2008 — 10:54 AM

Code:

for(getline(animReadFile,dataLine); dataLine.size()>0; getline(animReadFile,dataLine)) {

    // some code

}

The full example would be:

Code:

frame tempFrame;

tempFrame.texture = -1;

std::string tempString = "";

std::string dataLine;

char* stringPoint;

for(getline(animReadFile,dataLine); dataLine.size()>0; getline(animReadFile,dataLine))

   {

      for(stringPoint=(char*)dataLine.c_string(); *stringPoint!='\0'; stringPoint++)

      {

      //some code

      }

   //more code

   tempFrame.texture = -1;

   tempString = "";

   }

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