Question

I have the following while statement:

while ((leftSide.Count-rightSide.Count!=-1)&&(leftSide.Count-rightSide.Count!= 0))
{
     // Do stuff here
}

I would love to write this something like this:

while (leftSide.Count - rightSide.Count ! in [-1, 0])
{
     // Do stuff here
}

but that is illegal syntax. I am wondering, is there some way to that? Some syntax I don’t know?

I want to see if the difference of the counts in a set of numbers without having to re-include the whole left side of the statement again?

I suppose I could do this:

int x = leftSide.Count-rightSide.Count;
while ((x != -1) && (x != 0))
{
     // Do stuff here
     x = leftSide.Count-rightSide.Count;
}

but I would rather not.

If there is no way to do a “set” comparison does anyone know why? C# is such a full featured language that it seems odd to have something like this missing.

Answer 1

Using extension methods, you could easily create an In operator:

public static class Extensions
{
    public static Boolean In<T>(this T obj, params T[] items)
    {
        return items.Contains(obj);
    }
}

Usage:

Int32 i = 10;
i.In(10, 20, 30); // True