Thread: Iterator help

In the for() loop i would like to give a new name to the iterator at every loop like: it1,it2,it3 etc.
Would it be possible?

Code:

int main () 
{        
   char* str;
   string str2 = "tom";
   ifstream file ("1.txt");
   int length;
  
     // get length of file:
    file.seekg (0, ios::end);
    length = file.tellg();
    file.seekg (0, ios::beg);
            
    // allocate memory:
    str = new char [length];
            
    // read data as a block:
    file.read (str,length);
    file.close();
    
    myvector.push_back(str);
    
    
    for (i = 0; i<5; i++)
    {
         it(i) = search (myvector[0].begin(), myvector[0].end(), str2.begin(), str2.end());

              if (it(i) != myvector[0].end())
              {
                   myvector[0][distance(myvector[0].begin(),it(i))] = 
                                    toupper(myvector[0][distance(myvector[0].begin(),it(i))]);
              }    
    } 
   cout <<  myvector[0] << endl;       
   system("pause");
   return 0;
}

C++ does not support variable variables. Why do you want to do that anyway?

To save place, because i want to find every occurrances of the string in the file and otherwise
i should rewrite the search() uppercase() formula a lot of times.

Could you suggest another approach to this problem? Thanks!

You're not very specific.
Save time? Rewrite formula?
How would you use variable variables?

You have posted code similar to that.

What is the purpose of making a vector that contains a single string? What makes you think that char* types have a begin() and end() method (and why aren't you using a real string)?

I think I have once suggested to use the find() method of the string. To find all ocurrences of a string, use something like:

Code:

    string source(...), target(...);
    size_t pos = 0;
    while ((pos = source.find(target, pos)) != string::npos) {
        //do something with source at pos
        pos += target.size();
    }

Yes you already suggested to use find() but i thought that the find() method could only find the first occurrence.
So i used search() to find more but search takes a vector as argument thats why i used vector[0].
I couldnt compile search() with a string.

Im using char* types because the read() method didnt compile with a string.

Thanks!

Yes you already suggested to use find() but i thought that the find() method could only find the first occurrence.

If you look at the snippet I posted you'll see that find takes a second argument, the position to start search from. To find all occurrences you'd have to call find in a loop.
Anyway, wouldn't search only find the first match, as well, and you'd have to call it in a loop to find next matches (passing a different start iterator)?

So i used search() to find more but search takes a vector as argument thats why i used vector[0].

No, algorithms take ranges, doesn't matter whether they are vectors or not. You could pass it a string iterators (or char*) just as well. In fact that is what you are doing. (Although you have a vector, you are only working with the item at vector[0] and that's a plain string.)

Im using char* types because the read() method didnt compile with a string.

Fine by me but it looks like your buffer doesn't have room for terminating 0 character.

Thanks for the explanation, much appreciated!

Originally Posted by anon

Fine by me but it looks like your buffer doesn't have room for terminating 0 character.

I guess what you mean is that i cant use istream::read() and string::find() together because istream::read() reads character by character.
I hope there's a way to use them together it would be easier if you want to find several different targets on one line.
Otherwise i should use getline() with putting the targets in a vector i guess.

Edit : But its ok, i managed. Actually using getline() and vector takes up less place than using read().