C++ ???

/*
Hey internet,
I am trying to write a program that adds a number to the end of a filename.
*/

Code:

#include <ostream>
#include <iostream>
#include <string>
#include <sstream>

using namespace std;

int main()
{
    int dayNum = 0;          // Day number.
    string filenameString; // Holder for sequential filename suffix.
    ostringstream convert; // Holder for int daynum to string conversion.
    
    string repFilename = "FILENAME"; //f Name of File.
     
    cout << endl;
    cout << "Day Number: "; // Get the day number.
    cin >> dayNum;
    
    cout << endl;
    
    convert << dayNum; // Assing dayNum to covert.
    
    filenameString = convert.str();  // Change dayNum from int to string.
    
    filenameString = "_DAY_" + filenameString;
    // Add "_day_" to dayNum suffix.
    
    filenameString = repFilename + filenameString + ".txt";
    // Add file name + dayNum suffix.
    
    cout <<"\n";
    cout << "File name is = " << filenameString; // TEST 1
    cout <<"\n";
    
    // TEST 2. should make filename = FILENAME_DAY_2.txt.
    
    dayNum++; // Assign dayNum + 1 to covert.
    
    convert << dayNum; // Assing dayNum to covert.
    
    filenameString = convert.str(); // Change dayNum from int to string.
    
    filenameString = "_day_" + filenameString;
    // Add "_day_" to dayNum suffix.
    
    filenameString = repFilename + filenameString + ".txt";
    // Add file name + dayNum suffix.
    
    cout <<"\n";
    cout << "NEW File name is = " << filenameString.c_str(); // TEST
    cout <<"\n";
    cout <<"\n";

    // but the file name is = FILENAME_day_12.txt
    
} // END main.

// the first pass works great the second pass does not

 

I am not sure what I am missing but I have looked at.

http://www.cplusplus.com/reference/iostream/ostringstream/

and I tried flush() and clear() no luck.

 

Thanks

@Ap0ks,

Worked like a charm. Thank you for helping.