Question

I am looking for methods to generate random strings in C++.Here is my code:

string randomStrGen(int length) {
    static string charset = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
    string result;
    result.resize(length);

    srand(time(NULL));
    for (int i = 0; i < length; i++)
        result[i] = charset[rand() % charset.length()];

    return result;
}

But the seed(time(NULL)) is not random enough.Are there any other better way to generate random strings in C++?

Answer 1

Don’t call srand() on each function call – only call it once at first function call or program startup. You migh want to have a flag indicating whethersrand() has already been called.

The sugested method is good except that you misuse srand() and get predictably bad results.