?? ???? ??? ?? ??? ??? ???? ???? C#? ??? ????????. ?????? ?? ???? ??? ??? ??? ?????. ??? ??? ?? ??? ??? ?? ??? ?????. C#? ?? ???? ??? ??? ??? ??? ???? ??? ????.

C#? ?? ???

• ???? C#??? ??? ??? ??? ?????? ? ?? C# ??? ??????? Random Class? ????.
• Random ???? ?? ?? ??? ??????. ?? ? ???? ?? ??? ??? ?? ??? ??? ???? ??? ?? ??? ?????. ??? ??? ?? ??? ??? ? ????? ??? ??? ?? ??? ???? ??? ? ? ????? ?? ??? ??? ??? ????? ????? ???????.
• ???, ??? ??? ??? ??? ? ????. ?? ??? ?? ??? ???? ???? ??? ????? ???? ??? ??? ????? ????. ??? ?? ?? ??? ??? ??? ?????. ??? ???? ???? ????. ??? ??? ????. ?? ??? ??? ?? ?? ??? ??? ?? ??? ??????? ?????.

?? ? ??

???? ???? ??? ? ?? ?? ??? ????? ???????. ?? ?? ??? ?? ?? ??? ?????. ???? ??? ??? ????? ??? ??? ?? ??? ?????. ?? ???? ????? ?? ? ?????. ?? ???? ??? ??? ?????? ?? ?? ???? ?? ?? ??, ??? ?? ?? ??, ? ?? ???? ???? ??? ?? ??. ???? ???? ???? ??? ??? ??? ?? ??? ????? ????? ????? ???. ??? ????? ????? ??????.

?? ??? ??? ? ?? ?? ??? ? ???? ???. ?? ?? ?? ?? ???? ???. ??? ? ?? ?? ?? ???? ???.

C# Random Class? ?? ?????? ??? ?????, ?? ?? ?? ?????. ??? ?? ?? ??? ????? ??? ???????.

RNGCryptoServiceProvider ???

System.Security.Cryptography ??????? RNGCryptoServiceProvider ???? ????? ??? ? ?? ?? ??? ??? ? ????.

C#? ?? ??? ??

C#?? ??? ???? ? ?? ??? Random ???? ????? ????. ?? ???? ? ??? ? ??? ???? ??? ? ????.

• Random():??? ?? ?? ?? ???? Random ???? ??? ??????. ?? ?? ??? ?? ????????. ??? ?? ????? GUID ???? ???????.
• Random(Int32):???? ?? ?? ???? Random ???? ??? ??????. ???? ?? ??? ???? Random ???? Next() ???? ?????.
• Next():???? ?? ?? ?? Int32 ??? ?????.
• Next(Int32):???? ???? ?? ??? ?? ?? ?? Int32 ??? ?????.
• Next(Int32, Int32):???? ?? ??? ??? ?? ?? ?? Int32 ??? ?????.

C#? ?? ??? ??

??? ??? ???? ??? ?? ???????.

?? #1

?? ???? ??? Int32 ??? ?????.

??:

using System;
public class Program
{
public static void Main()
{
Random rnd = new Random();
for (int i = 0; i < 10; i++)
Console.WriteLine("Random number {0} : {1}", i + 1, GenerateRandomInt(rnd));
}
public static int GenerateRandomInt(Random rnd)
{
return rnd.Next();
}
}

??:

?? #2

?? ???? 0~100 ??? ??? Int32 ??? ?????.

??:

using System;
public class Program
{
public static void Main()
{
Random rnd = new Random();
for (int i = 0; i < 10; i++)
Console.WriteLine("Random number {0} : {1}", i + 1, GenerateRandomInt(rnd));
}
public static int GenerateRandomInt(Random rnd)
{
return rnd.Next(100);
}
}

??:

?? #3

?? ???? 50~100 ??? ??? Int32 ??? ?????.

??:

using System;
public class Program
{
public static void Main()
{
Random rnd = new Random();
for (int i = 0; i < 10; i++)
Console.WriteLine("Random number {0} : {1}", i + 1, GenerateRandomInt(rnd));
}
public static int GenerateRandomInt(Random rnd)
{
return rnd.Next(50, 100);
}
}

??:

C#?? ?? ??? ?? ??

?? ?? ??? ??? ???? ??? ?? ???????.

?? #1

?? ???? ??? Int32 ??? ?????.

??:

using System;
public class Program
{
public static void Main()
{
Random rnd = new Random();
for (int i = 0; i < 10; i++)
Console.WriteLine("Random number {0} : {1}", i + 1, GenerateRandomInt(rnd));
}
public static double GenerateRandomInt(Random rnd)
{
return rnd.NextDouble();
}
}

??:

A Very Common Mistake

The most common mistake developers commit while generating random numbers is that for each random number, they create a new object of Random Class. As illustrated in the example below:

Example #1

Code:

using System;
public class Program
{
public static void Main()
{
for (int i = 0; i < 10; i++)
Console.WriteLine("Random number {0} : {1}", i + 1, GenerateRandomInt());
}
public static int GenerateRandomInt()
{
Random rnd = new Random();? //a very common mistake
return rnd.Next();
}
}

Output:

How Random Numbers are all the same and Why did this happen?

As explained in the working of Random Class, the numbers generated are based on the seed value and the current state of the machine. Any instance of Random class starts with the seed value, saves the current state and uses it to generate the next random number. In the code above, the mistake was to create a new instance of the Random class in every iteration of the loop. So, before the time in the internal clock changes, the code is fully executed, and each instance of Random class is instantiated with the same seed value. This results in the same set of numbers generated every time.

Conclusion

In this article, we learnt about the random number generator in C# and how it internally works to generate random numbers. We also briefly learnt the concept of pseudo-random and secure-random numbers. This information is sufficient for developers to use the Random class in their applications. Deep dive, if interested to explore more on random numbers for passwords and one-time passwords.

? ??? C#? ?? ???? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!