im learning loops

im learning loops and i just have a couple of questions so im perfectly clear on whats going on.

ive read a tutorial on for, while & do, and i figured the best type of loop to use to count the amount of files in a folder would be do, as it checks the condition at the end

Code:

---

void __fastcall TForm1::Button1Click(TObject *Sender)
{
int a = 0;
AnsiString filepath;
filepath = "\\\\server\\FMRS\\QC\\12-13\\*.*";
  TSearchRec sr;
  int iAttributes = 0;

        if (FindFirst(filepath,iAttributes,sr)== 0);
  {
  do
{
a++;
Edit1->Text = a;
}
while (FindNext(sr)== 0);
}
}

---

now i understand whats going on above apart from

Code:

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== 0

---

what exactly is this for? i know that == 0 means to set it as 0 , but what is it setting to 0? just playing around i removed the ==0 to see what happens.. not suprisingly it copiled, but did not give the correct results.

also, by adding

Code:

---

iAttributes |= faAnyFile ;

---

to the above will search for any file type , may they be hidden etc etc

but iattributes, i declared as a variable above .. so why am i putting |= faNyFile; afterwards .... variables only take numbers, so is faAnyFile giving it a value?

Quote:

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Originally Posted by Brad.G

now i understand whats going on above apart from

Code:

---

== 0

---

what exactly is this for? i know that == 0 means to set it as 0 , but what is it setting to 0? just playing around i removed the ==0 to see what happens.. not suprisingly it copiled, but did not give the correct results.

---

No, == 0 does not 'set it as 0', but it compares it to 0. So, the loop says "do while the result of FindNext equals 0".

- petter

ive most probably got the wrong end of the stick here..

so it compares it to zero.. it compares findfirst to zero ? , and findnext to zero ?

why would the value of findfirst or findnext change?

nvm

Return Value

findfirst returns 0 on successfully finding a file matching the search pathname.

When no more files can be found, or if there is an error in the file name:

-1 is returned

ahhhhh hang on!

so if findnext becomes -1 when nothing can be found, could this be used to start a search on the next directory?

[code]
if (Findnext==-1)
{
filepath = "\\\\server\\FMRS\\QC\\12-13\\*.*";
}

but would this start the loop again?

Quote:

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Originally Posted by Brad.G

why would the value of findfirst or findnext change?

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Because the parameter changes.

Quote:

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Originally Posted by Brad.G

so if findnext becomes -1 when nothing can be found, could this be used to start a search on the next directory?

[code]
if (Findnext==-1)
{
filepath = "\\\\server\\FMRS\\QC\\12-13\\*.*";
}

but would this start the loop again?

---

guess not, i just tried it

Quote:

---

Originally Posted by Brad.G

Code:

---


    if (FindFirst(filepath,iAttributes,sr)== 0);
    {
        do
        {
            a++;
            Edit1->Text = a;
        }
        while (FindNext(sr)== 0);
    }

---

---

Please note that no matter what if-sentence returns, program goes into the do-while -loop. Why? Because there is a semioclon ( ; ) at the end of if -line.

ahh... thanks for that eero, completely over looked that

Quote:

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Originally Posted by Brad.G

ahh... thanks for that eero, completely over looked that

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No problemo. :) Small things are (too) often easily missed.