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Re: Difference between for and while loop



On Fri, Apr 18, 2003 at 12:58:43PM +0300, Aryan Ameri wrote:
> On Friday 18 April 2003 03:52, tjm3 wrote:
> > This is the way it was explained to me.
> >
> > A FOR loop is usually used to execute a routine or instruction(s) a
> > fixed number of times, 'fixed' meaning that going into the loop, you
> > already know how many iterations will be made.  The FOR loop should
> > also be used when you know that you will be executing the contents of
> > the loop at least once.
> 
> Well, the way it has been explained to me, you can also use the FOR loop 
> in non defined loops, and you can also set a FOR loop, in a way that 
> the minimum execution time might be less than 1, say 0.

What language are we talking about ?

- sh : for loops loop a variable over a number of values ( i.e. for i in 1 2 3 )
  and while loops loop until a condition is met

- C : they are equivalent. Only the notation differs, and which one to
  use in a certain context is mostly a question of style and coding
  rules.
  The following is a perfectly valid use of for, but it is slightly
  unconventional

  int f;
  char buf[3];
  for(f=open("/tmp/file",O_RDONLY);read(f,buf,1)>0;)
  {
  }
  close(f);

- pascal : for loops are for numbers and enumerated types, while loops
  use a condition

- basic : somewhat like pascal

- theoretical : both while and for loops are unneeded : recursion is
  much nicer

Frank
   
> 
> I am not a professional programmer though
> 
> Cheers 
> 
> -- 
> /* Impeach God */
> 			--RMS
> Aryan Ameri
> 
> 
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