Thread: Help to make a loop.

Ok, it might seem a little complicated.
Please concentrate on the most inner part of the loop.
Once i get to else(), i would like to break out of while() and from the for() loop too.
But if i put a second "break;" outside of while(), it will break me out of for() even when i come out of if(), which i dont want. Once out of if() i want it to go back to for().
Maybe this is the case to use the unfamous "goto" ?

Code:

#include <string>
#include <cctype>
#include <vector>
#include <fstream>
#include <iostream>
using namespace std;

void openFile(ifstream& file){
          
        file.clear();
        for(;;)
        {
            string fileName;
            cout << "Enter the name of your file: " ;
            cin >> fileName;
            file.open(fileName.c_str());
            if (file.good())
            {
                break;
            }
            cerr << "\nThere is no file, named --> " << fileName << " <-- in your folder.\n\n" << endl;
        file.clear();
        }
}
   
int main ()
{   
   ifstream  file1;
   openFile(file1);
   ifstream  file2 ("List of proper nouns.txt");
   ifstream  file3 ("List of proper nouns preceeding words.txt");
   ofstream TheCopy;
   TheCopy.open ("Your_Uppercased_Proper_Nouns_Copy.srt",ios::app);
   string str;
   vector<string> vProperNouns;
   vector<string> vPreceeding;        //vProperNounsPrecedingWords
      
   while (getline(file2, str))
   {        
       vProperNouns.push_back(str);
   }
   file2.close();
   while (getline(file3, str))
   {        
       vPreceeding.push_back(str);
   }
   file3.close();
   
  //write a line into str
   while (getline(file1, str))
   {            
         BreakLoop:
         for ( string::size_type i = 0; i < vProperNouns.size(); i++)
         {     //search for proper noun in str    
               string::size_type pos = 0;
               while (( pos = str.find(vProperNouns[i], pos)) != string::npos)
               {     
                     for ( string::size_type j = 0; j < vPreceeding.size(); j++)
                     {   //search for preceeding word before proper noun
                         string::size_type loc = 0;
                         while((loc = vProperNouns[i].rfind(vPreceeding[j],pos)) != string::npos)
                         {
                             // the one it found is just not before the proper noun: go back to for().
                             if ( loc < (pos - (vPreceeding[j].size()+ 1))) 
                             {    
                                 break;
                             }  
                             //the one it found is just before the proper noun: break out of while() and out of for() too.
                             else  
                             {                                            
                                 pos += str.size();
                                 goto BreakLoop;
                             }              
                         }
                      loop: break;   
                     }
               str[pos] = toupper (str[pos]);               
               }
         }
         cout<<str<<endl;
         //TheCopy << str << endl;
   }
   file1.close();
   TheCopy.close();
   system("pause");
   return 0;
}

One way would be to uses goto and jump to a label named "BreakLoop" or something descriptive along the lines of that. Put it directly outside the loop.
Otherwise you need a variable and use two breaks.

Thank you!

Originally Posted by Elysia

Otherwise you need a variable and use two breaks.

A variable? To do what with it?

A variable? To do what with it?

To control the outer loop.

There is another possibility: to place the relevant code in a function and call that function. Of course, the difference is arguably cosmetic: instead of a goto with a label after the loop, you use a return. On the other hand, this may actually help to make the code easier to read by abstracting away a block of code into a function, thus providing it a name.

Thank you Laserlight!
This function solution sounds good but a bit hard for me to write it right now, maybe later.

This loop control with a variable, i never heard of it.
In what section of any tutorials should i search for it?

This loop control with a variable, i never heard of it.

In its simplest form:

Code:

bool flag = true;
while (flag)
{
    // ...
}

In reality, what to use depends on the situation. You could even use one such variable that participates in the loop condition of all the loops (with &&).

Thanks, i'll try that one.