Why Static method sometimes returns same result for separate call?

Question

In my c# code I have a static method. Here is the code sample:

public class RandomKey
{
    public static string GetKey()
    {
        Random rng = new Ran         


        

Answer 1

The reason is that you are initializing the Random object inside the method.
When you call the method in close time proximity (like inside a loop), the Random object is initialized with the same seed. (see Matthew Watson's comment to find out why.)
To prevent that you should declare and initialize the Random object as a static field, like this:

public class RandomKey
{
    static Random rng = new Random();

    public static string GetKey() 
    {
    // do your stuff...
    }
}