How to generate a random 10 digit number in C#?

I’m using C# and I need to generate a random 10 digit number. So far, I’ve only had luck finding examples indicating min maximum value. How would i go about generating a random number that is 10 digits, which can begin with 0, (initially, I was hoping for random.Next(1000000000,9999999999) but I doubt this is what I want).

My code looks like this right now:

[WebMethod]
public string GenerateNumber()
{
    Random random = new Random();
    return random.Next(?);
}

**Update ended up doing like so,

[WebMethod]
public string GenerateNumber()
{
    Random random = new Random();
    string r = "";
    int i;
    for (i = 1; i < 11; i++)
    {
        r += random.Next(0, 9).ToString();
    }
    return r;
}

Answers:

Thank you for visiting the Q&A section on Magenaut. Please note that all the answers may not help you solve the issue immediately. So please treat them as advisements. If you found the post helpful (or not), leave a comment & I’ll get back to you as soon as possible.

Method 1

Use this to create random digits with any specified length

public string RandomDigits(int length)
{
    var random = new Random();
    string s = string.Empty;
    for (int i = 0; i < length; i++)
        s = String.Concat(s, random.Next(10).ToString());
    return s;
}

Method 2

try (though not absolutely exact)

Random R = new Random();

return ((long)R.Next (0, 100000 ) * (long)R.Next (0, 100000 )).ToString ().PadLeft (10, '0');

Method 3

If you want ten digits but you allow beginning with a 0 then it sounds like you want to generate a string, not a long integer.

Generate a 10-character string in which each character is randomly selected from ‘0’..’9′.

Method 4

To get the any digit number without any loop, use Random.Next with the appropriate limits [100…00, 9999…99].

private static readonly Random _rdm = new Random();
private string PinGenerator(int digits)
{
   if (digits <= 1) return "";

   var _min = (int)Math.Pow(10, digits - 1);
   var _max = (int)Math.Pow(10, digits) - 1;
   return _rdm.Next(_min, _max).ToString();
}

This function calculated the lower and the upper bounds of the nth digits number.

To generate the 10 digit number use it like this:

PinGenerator(10)

Method 5

private void button1_Click(object sender, EventArgs e)
{
   Random rand = new Random();
   long randnum2 = (long)(rand.NextDouble() * 9000000000) + 1000000000;
   MessageBox.Show(randnum2.ToString());
}

Method 6

I came up with this method because I dont want to use the Random method :

public static string generate_Digits(int length)
{
    var rndDigits = new System.Text.StringBuilder().Insert(0, "0123456789", length).ToString().ToCharArray();
    return string.Join("", rndDigits.OrderBy(o => Guid.NewGuid()).Take(length));
}

hope this helps.

Method 7

// ten digits 
public string CreateRandomNumber
{
    get
    {
        //returns 10 digit random number (Ticks returns 16 digit unique number, substring it to 10)
        return DateTime.UtcNow.Ticks.ToString().Substring(8); 
    }
}

Method 8

(1000000000,9999999999) is not random – you’re mandating that it cannot begin with a 1, so you’ve already cut your target base by 10%.

Random is a double, so if you want a integer, multiply it by 1,000,000,000, then drop the figures after the decimal place.

Method 9

private static Random random = new Random((int)DateTime.Now.Ticks);//thanks to McAden

public long LongBetween(long maxValue, long minValue)
{
    return (long)Math.Round(random.NextDouble() * (maxValue - minValue - 1)) + minValue;
}

Method 10

I tried to write a fast one:

private int GetNDigitsRandomNumber(int digits)
{
    var min = 1;
    for (int i = 0; i < digits-1; i++)
    {
          min *= 10;
    }
    var max = min * 10;

    return _rnd.Next(min, max);
}

Method 11

Here is a simple solution using format string:

string r = $"{random.Next(100000):00000}{random.Next(100000):00000}";

Random 10 digit number (with possible leading zeros) is produced as union of two random 5 digit numbers. Format string “00000” means leading zeros will be appended if number is shorter than 5 digits (e.g. 1 will be formatted as “00001”).

For more about the “0” custom format specifier please see the documentation.

Method 12

Random random = new Random();
string randomNumber = string.Join(string.Empty, Enumerable.Range(0, 10).Select(number => random.Next(0, 9).ToString()));

Method 13

To generate a random 10 digit number in C#

Random RndNum = new Random();   

int RnNum = RndNum.Next(1000000000,9999999999);

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0