Question

I want to generate 25 unique random numbers and list them in a console. The numbers should be atleast 10 characters long. Any easy way to do that?

Answer 1

Try building the numbers up as strings, and use a HashSet to ensure they are unique:

Random random = new Random();
HashSet<string> ids = new HashSet<string>();

while (ids.Count < 25)
{
    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < 10; ++i)
    {
        sb.Append(random.Next(10));
    }
    ids.Add(sb.ToString());
}

Example output:

7895499338
2643703497
0126762624
8623017810
...etc...

The class HashSet is present in .NET 3.5 and newer.