how to place a "double" formated to 6 decimal digits into a QString?

Question

I want to place a double into a QString with a format that yields 6 decimal digits.

ie. %1.6f

This crashes with memory dump:

char *x = (char*)malloc(20 * sizeof(char));

    for(int i; i < m_iBuild; i++){
        std::fill_n(x, 20, '\0');
        sprintf(x, "%1.12f", dLog[i]);
        out << x << "\t" << msgList.at(cLog[i]) << "\n";
}

If I just placed dLog[i] into the stream I get scientific notation of 5 digits.

Answer 1

This is what I did to get 888888.888888:

 for(int i; i < m_iBuild; i++){
        out << QString::number(dLog[i] - dLog[0], 'f', 6) << "\t" << msgList.at(cLog[i]) << "\n";
    }