Generate random password for one-time password verification

November 9, 2022

I had to generate random password for temporary entry/login purpose in C#. Now I need to only send 6 digits but no more characters, or special characters. New to the C# world. Hence, I am providing what I have so far.

helper.cs

public static string GenerateRandomPassword()
{
    int numsLength = 6;
    
    const string nums = "0123456789";
    StringBuilder sb = new StringBuilder();
    Random rnd = new Random();

    for (int i = 0; i < charLength; i++)
    {
        int index = rnd.Next(chars.Length);
        sb.Append(chars[index]);
    }
    int numindex = rnd.Next(nums.Length);
    sb.Append(nums[numindex]);

    return sb.ToString();
}

I think my logic is still not right. I know that I should not use String Builder since I only want to send digits. Can anyone help me and figure out my mistake by editing the above codes?

>Solution :

You could also just concatenate strings and do something like:

public static string GenerateRandomPassword()
{
    int numsLength = 6;

    const string nums = "0123456789";
    string tempPass = string.Empty;
    Random rnd = new Random();

    for (int i = 1; i <= numsLength; i++)
    {
        int index = rnd.Next(nums.Length);
        tempPass += nums[index];
    }

    return tempPass;
}