I want to generate random number, which is 9 digits including leading zero if the number is less than 9 digits, say 123 will be 000000123. I have the following code which doesn't include leading zero :
Dim RandomClass As New Random()
Dim RandomNumber = RandomClass.Next(1, 999999999)
Thanks.
EDIT: While I still quite like my "individual digits" approach below, there's an easier way - just give a custom number format:
C#:
Random rng = new Random();
int number = rng.Next(1, 1000000000);
string digits = number.ToString("000000000");
Console.WriteLine(digits);
VB:
Dim rng As New Random
Dim number As Integer = rng.Next(1, 1000000000)
Dim digits As String = number.ToString("000000000")
Console.WriteLine(digits)
EDIT: As has been pointed out in the comments, a format string of D9 will also do the job:
Dim digits As String = number.ToString("D9")
Personally I'd have to look up exactly what that would do, whereas I'm comfortable with custom number formats - but that says more about me than about the code :)
Rather than generating a single number between 1 and 999999999, I would just generate 9 numbers between 0 and 9. Basically you're generating a string rather than a number (as numerically 000000000 and 0 are equivalent, but you don't want the first).
So generate 9 characters '0' to '9' in a Character array, and then create a string from that.
Here's some sample C# code:
using System;
class Test
{
static void Main(string[] args)
{
Random rng = new Random();
string digits = GenerateDigits(rng, 9);
Console.WriteLine(digits);
}
static string GenerateDigits(Random rng, int length)
{
char[] chars = new char[length];
for (int i = 0; i < length; i++)
{
chars[i] = (char)(rng.Next(10) + '0');
}
return new string(chars);
}
}
... and converting it to VB:
Public Class Test
Public Shared Sub Main()
Dim rng As New Random
Dim digits As String = Test.GenerateDigits(rng, 9)
Console.WriteLine(digits)
End Sub
Private Shared Function GenerateDigits(ByVal rng As Random, _
ByVal length As Integer) As String
Dim chArray As Char() = New Char(length - 1) {}
Dim i As Integer
For i = 0 To length - 1
chArray(i) = Convert.ToChar(rng.Next(10) + &H30)
Next i
Return New String(chArray)
End Function
End Class
One point to note: this code can generate "000000000" whereas your original code had a minimum value of 1. What do you actually want the minimum to be?
You need to declare your variable as type string. Integer can't have leading zero. Check my sample below:
Dim RandomClass As New Random()
Dim randomString As String
For i = 1 To 1000 Step 1
randomString = RandomClass.Next(1, 999999999).ToString
If randomString.Length < 9 Then
randomString = randomString.PadLeft(9, "0")
End If
Response.Write(randomString & "<br/>")
Next
Is 999999999 a legal value? If so...
'
Dim myRand As New Random
'
Private Function NineDigitRand() As String
'return a numeric string between 000000001 and 999999999 inclusive
Return myRand.Next(1, 1000000000).ToString("d9")
End Function
