Check if List values are consecutive

Question

List dansConList = new List();
dansConList[0] = 1;
dansConList[1] = 2;
dansConList[2] = 3;

List dansRandomList = new List

        

Answer 1

Here is an extension method that uses the Aggregate function.

public static bool IsConsecutive(this List value){
    return value.OrderByDescending(c => c)
                .Select(c => c.ToString())
                .Aggregate((current, item) => 
                            (item.ToInt() - current.ToInt() == -1) ? item : ""
                            )
                .Any();
}

Usage:

var consecutive = new List(){1,2,3,4}.IsConsecutive(); //true
var unorderedConsecutive = new List(){1,4,3,2}.IsConsecutive(); //true
var notConsecutive = new List(){1,5,3,4}.IsConsecutive(); //false