Qt/c++ random string generation

Question

I am creating an application where I need to generate multiple random strings, almost like a unique ID that is made up of ASCII characters of a certain length that have a mix of uppercase/lowercase/numerical characters.

Are there any Qt libraries for achieving this? If not, what are some of the preferred ways of generating multiple random strings in pure c++?

possible duplicate of [Create a random string or number in Qt4](http://stackoverflow.com/questions/3244999/create-a-random-string-or-number-in-qt4) also see [How do I create a random alpha-numeric string in C++?](http://stackoverflow.com/questions/440133/how-do-i-create-a-random-alpha-numeric-string-in-c) — Shafik Yaghmour, Sep 18 '13 at 02:45

score 28 · Answer 1 · edited Mar 01 '15 at 13:50

28

You could write a function like this:

QString GetRandomString() const
{
   const QString possibleCharacters("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
   const int randomStringLength = 12; // assuming you want random strings of 12 characters

   QString randomString;
   for(int i=0; i<randomStringLength; ++i)
   {
       int index = qrand() % possibleCharacters.length();
       QChar nextChar = possibleCharacters.at(index);
       randomString.append(nextChar);
   }
   return randomString;
}

edited Mar 01 '15 at 13:50

eebbesen

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answered Sep 18 '13 at 07:48

TheDarkKnight

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2

Very great solution, although I'm having a problem where the answer isn't random each time I run the program (even after closing and opening QT Creator)... Any idea what could be causing this? – Barry Michael Doyle Feb 27 '15 at 22:21
4

@BarryDoyle, you may need to seed the random number generator with qsrand http://qt-project.org/doc/qt-4.8/qtglobal.html#qsrand – TheDarkKnight Mar 02 '15 at 09:14
I figured it out and that was the issue, thanks... – Barry Michael Doyle Mar 02 '15 at 16:27

Qt/c++ random string generation

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