Printing to file / Output issues

This is a discussion on Printing to file / Output issues within the C++ Programming forums, part of the General Programming Boards category; I'm trying to make a program that outputs every hour and minute of the day in hh:mm format and then ...

  1. #1
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    Question Printing to file / Output issues

    I'm trying to make a program that outputs every hour and minute of the day in

    hh:mm format and then print all of that to a text file.

    However, I have no idea how to make it go about printing it as

    00:00
    00:01
    00:02 and so on.

    Any help would be appreciated, as well as how to make it write every single timestamp to a text file.

    Thanks in advance.

    Code:
    #include <iostream>
    #include <fstream>
    #include <iomanip>
    
    using namespace std;
    
    int main ()
    {
      int n;
      int m;
      cin >> n;
          while (n>-2 && n<24)
          {
          cout << setfill('0') << setw(2) << ++n << "";
          }
      cin >> m;
          while (m>-2 && m<60)
          {
      cout << setfill('0') << setw(2) << ++m << "";
           }
      cout << n << ":" << m;
      system("PAUSE");
      EXIT_SUCCESS;
    }

  2. #2
    and the hat of wrongness Salem's Avatar
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    A for loop which counts the hours, and within that, a for loop which counts the minutes.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
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    I am new to c++ and a noob at it, could you help me out a little more than that, pretty please?

  4. #4
    and the hat of wrongness Salem's Avatar
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    Why?
    Since you spent less than a minute to reply rather than going away to look at some reference material to see if you could manage it yourself.

    You've already managed the hard part (IMO) of making cout output leading zeros.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

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    Because I messed around with it a lot before coming to ask for help. I wouldn't come and ask for help if I had a clue.

  6. #6
    Its hard... But im here swgh's Avatar
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    On a side note dont use system("pause"); system calls are unsafe.

    Use std::cin,get(); to freeze the console output. If your using std::cin >> as you are in this program depending on your compiler you may have to add std::cin.ignore() underneath you ignore the whitespace.
    I'm just trying to be a better person - My Name Is Earl

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    Ah, thank you kindly for the tip. I will use that from now on. =)

  8. #8
    and the hat of wrongness Salem's Avatar
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    So
    for ( m = 0 ; m < 10 ; m++ )
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

  9. #9
    Registered User hk_mp5kpdw's Avatar
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    This is a real simple program, the basic outline is:
    • Open output file
    • for loop through the hours (0-23 inclusive)
      • for loop through the minutes (0-59 inclusive)
        • print hour/minutes in HH:MM format using cout
        • print same thing a above, but to file this time

    So, read up on for loops and nested loops along with some file I/O using fstream objects and you're done.
    "Owners of dogs will have noticed that, if you provide them with food and water and shelter and affection, they will think you are god. Whereas owners of cats are compelled to realize that, if you provide them with food and water and shelter and affection, they draw the conclusion that they are gods."
    -Christopher Hitchens

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    Code:
    #include <iostream>
    #include <fstream>
    #include <iomanip>
    
    using namespace std;
    
    int main ()
    {
        int hh;
        int mm;
        for ( mm = 0 ; mm < 59 ; mm++)
        for ( hh = 0 ; hh < 24 ; hh++)
        
        ofstream myfile;
        myfile.open ("TimeStamps.txt");
        cout.fill('0');
        myfile.fill('0');
        myfile << setw(2) << mm << ":" << hh;
        cout.fill(' ');
        myfile.fill(' ');
        myfile.close;
    Changed it up a little, but it gives me the error of:

    "14 C:\Dev-Cpp\Practice\Time1.cpp `myfile' undeclared (first use this function)"

  11. #11
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    Code:
    >    ofstream myfile;
    >    myfile.open ("TimeStamps.txt");
    You need to move these lines outside the for-loop. Otherwise the scope of myfile is only within the loop. Also:
    Code:
    >    myfile.close;
    Should be:
    Code:
        myfile.close();

  12. #12
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    Like this?

    Code:
    #include <iostream>
    #include <fstream>
    #include <iomanip>
    
    using namespace std;
    
    int main ()
    {
        int hh;
        int mm;
            
        ofstream myfile;
        myfile.open ("TimeStamps.txt");
        for ( mm = 0 ; mm < 59 ; mm++)
        for ( hh = 0 ; hh < 24 ; hh++)
    
        cout.fill('0');
        myfile.fill('0');
        myfile << setw(2) << hh << ":" << mm;
        cout.fill(' ');
        myfile.fill(' ');
        myfile.close();
    It's only outputting this: "24:59"
    Not sure what is wrong with it now.

  13. #13
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    >It's only outputting this: "24:59"
    This is true. A for-loop only executes a single statement, unless you include braces to indicate otherwise. This is one reason it's important to properly indent one's code.

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    Your loops need braces around the code that is supposed to be in the loop. Otherwise, only the next statement will be a part of that loop. In this case, that means that your loops only execute the cout.fill('0'); line over and over again 1500 times, then execute the code after it once.

    BTW, your first loop should probably stop at 60, not 59.

  15. #15
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    I have no idea how to go about fixing that. Could you point me into the right direction or something? And I didn't think the indents were a big deal on small code, usually pretty easy to follow, no?

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