im learning loops

[Brad.G]

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

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

== 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

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?