How can i generate different unique string in different length

anjumathi kumar

15y2.4k.NET

{
public static string createRandomString(int Length)string _allowedChars = "abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ";Random randNum = new Random();int outputLength = (int)(randNum.NextDouble() * Length); //<<<<<<<<< moved out of loop

char[] chars = new char[outputLength]; //<<<<<<<< use outputLength here

// not used int allowedCharCount = _allowedChars.Length;

{
chars[i] = _allowedChars[(
}

}
for (int i = 0; i < outputLength; i++)int)((_allowedChars.Length) * randNum.NextDouble())];return new string(chars);

Hi,

This code generates same string some time and different string some time

this is random generate code function.

how can i change if i want different string in different length always?

5 Replies

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Sam Hobbs15y ago
Note that one important difference between the original code and Vulpes's is that the original code creates a new Random object many times whereas Vulpes's (the console version) creates it only once. I am not sure about the otehr version that is intended for use in ASP; it creates a new Random object each time the button is pressed and I am not sure if that will be random enough. I assume it will be due to use of a seed.
0
Vulpes15y ago
Suppose when you press a button, the number of random strings to be generated is taken from a textbox and the random strings are then displayed in a listbox. The code to do that in an ASP.NET application would be:

protected void Button1_Click(object sender, EventArgs e)
{
int numStrings;
int.TryParse(TextBox1.Text, out numStrings);
if (numStrings <= 0)
numStrings = 1;
else if (numStrings > 30) // maximum of 30 strings, say
numStrings = 30;
Random rand = new Random(DateTime.Now.Millisecond);
string[] strings = new string[numStrings];
string allowedChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
int num = 0;

while (num < numStrings)
{
int stringLength = rand.Next(1, 21); // between 1 and 20 characters say
char[] chars = new char[stringLength];
for (int i = 0; i < stringLength; i++)
{
chars[i] = allowedChars[rand.Next(52)];
}
string s = new string(chars);
if (Array.IndexOf(strings, s) == -1)
{
strings[num] = s;
num++;
}
}

ListBox1.Items.Clear();
for (int i = 0; i < strings.Length; i++) ListBox1.Items.Add(strings[i]);
}

Incidentally, I've assumed that it doesn't matter if there is more than one string with the same length as long as they're unique. If you want the lengths to be unique, then this is easy to adjust for.
0
anjumathi kumar15y ago
using System;

class Test
{
static Random rand = new Random();
static string[] strings;
static string allowedChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

static void Main()
{
Console.Write("Enter number of unique strings to generate (max 30) : ");
int numStrings = int.Parse(Console.ReadLine());
if (numStrings > 30) numStrings = 30;
strings = new string[numStrings];
int num = 0;
while (num < numStrings)
{
int stringLength = rand.Next(1, 21); // between 1 and 20 characters say
char[] chars = new char[stringLength];
for (int i = 0; i < stringLength; i++)
{
chars[i] = allowedChars[rand.Next(52)];
}
string s = new string(chars);
if (Array.IndexOf(strings, s) == -1)
{
strings[num] = s;
num++;
}
}

Console.WriteLine();
foreach(string s in strings) Console.WriteLine(s);
Console.ReadKey();
}
}

i want the code in asp.net c#

how can i write the code in asp.net c#
0
15y ago
When you use the random function to get the string there is a chance of selecting the same string again.

Once the string is genereated from where you're are comparing the newly generated string with the old one. There if the string is already present call the same function again to generate the new one.

Have you tried System.Guid.NewGuid().ToString() ?

Hope you got the idea.
0
Vulpes15y ago
Try this:

using System;

class Test
{
static Random rand = new Random();
static string[] strings;
static string allowedChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";

static void Main()
{
Console.Write("Enter number of unique strings to generate (max 30) : ");
int numStrings = int.Parse(Console.ReadLine());
if (numStrings > 30) numStrings = 30;
strings = new string[numStrings];
int num = 0;
while (num < numStrings)
{
int stringLength = rand.Next(1, 21); // between 1 and 20 characters say
char[] chars = new char[stringLength];
for (int i = 0; i < stringLength; i++)
{
chars[i] = allowedChars[rand.Next(52)];
}
string s = new string(chars);
if (Array.IndexOf(strings, s) == -1)
{
strings[num] = s;
num++;
}
}

Console.WriteLine();
foreach(string s in strings) Console.WriteLine(s);
Console.ReadKey();
}
}
0