How to Refactor this if condition

Question

Is there a better way to refactor this if condition? or just leave it alone?

if (buttonindex == 1 || buttonindex == 4 || buttonindex == 10 || buttonindex == 12 || buttonindex == 14 || buttonindex == 15 || buttonindex == 17|| buttonindex == 18) 
{
 dosomething();
}

Answer 1

You could declare an array with the valid indexes like

int[] validIndexes = new int[] { 1, 4, 10, 12, 14, 15, 17, 18 };

And then use it like this

if (validIndexes.Contains(buttonindex))
{
    dosomething();
}