Check out example codes for "int random string generator c++". It will help you in understanding the concepts better.

Code Example 1

string  gen_random(int len) {
        string s;
        static const char alphanum[] =
            "0123456789"
            "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
            "abcdefghijklmnopqrstuvwxyz";

        for (int i = 0; i < len; ++i) {
            s+= alphanum[rand() % (sizeof(alphanum) - 1)];
             }

     return s;

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