To generate Random numbers from 1- 20 I need to pick selective and it should not be repetitive.
How to do this in C#
Note I need to loop through as like this
Random rnd = new Random()
rnd.Next(1,20)
for(int i =0; i<=20;i++)
{
}
For all the loops number should be 1 to 20
I did one this way awhile back. I don't know how it compares to the other methods presented as far as efficiency, randomness, etc. But it seems to work:
List<int> integers = new List<int>() { 1, 2, 3, 4, 5, 6,7, 8, 9, 10, 11, 12 };
Random rnd = new Random();
var ints = from i in integers
orderby rnd.Next(integers.Count)
select i;
This method will generate all the numbers, and no numbers will be repeated:
/// <summary>
/// Returns all numbers, between min and max inclusive, once in a random sequence.
/// </summary>
IEnumerable<int> UniqueRandom(int minInclusive, int maxInclusive)
{
List<int> candidates = new List<int>();
for (int i = minInclusive; i <= maxInclusive; i++)
{
candidates.Add(i);
}
Random rnd = new Random();
while (candidates.Count > 0)
{
int index = rnd.Next(candidates.Count);
yield return candidates[index];
candidates.RemoveAt(index);
}
}
You can use it like this:
Console.WriteLine("All numbers between 0 and 20 in random order:");
foreach (int i in UniqueRandom(0, 20)) {
Console.WriteLine(i);
}
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