Amateur square root source code

double number_input;

    cout << "Insert the number that you want to get the square root of: ";
    cin >> number_input;

    double result = 0;
    bool flag = true;
    double iterator_;

    while(flag == true)
    {
        iterator_++;
        result = iterator_ * iterator_;

        if(result == number_input)
        {
            break;
        }
    }

    cout<< iterator_;