Split a List into groups of consecutive numbers [closed]

Answer 1

Try the following code;

public static IEnumerable> GroupConsecutive(this IEnumerable source)
{
    if (!source.Any()) { yield break;}
    var prev = source.First();
    var grouped = new List(){ prev };
    source = source.Skip(1);
    while (source.Any())
    {
        var current = source.First();
        if (current - prev != 1)
        {
            yield return grouped;
            grouped = new List();
        }
        grouped.Add(current);
        source = source.Skip(1);
        prev = current;
    }
    yield return grouped;
}

var numbers = new[] { 1, 2, 3, 4, 6, 7, 9 };
var result = numbers.GroupConsecutive();

Output
1,2,3,4
6,7
9