Returns the last n
elements in a collection.
Use IEnumerable.Count()
to check if the enumerable is non-empty.
Use IEnumerable.Skip(list.Count() - n)
to get the last n
elements.
If the enumerable object is empty, return the default()
value for the given enumerable.
Omit the second argument, n
, to use a default value of 1
.
代码实现
public static partial class _30s
{
public static IEnumerable<T> GetLastN<T>(IEnumerable<T> list, int n = 1)
{
return list.Count() != 0 ? list.Skip(list.Count() - n) : default(IEnumerable<T>);
}
}
使用样例
List<int> nums = new List<int> { 1, 2, 3, 4, 5 };
_30s.GetLastN(nums); // { 5 }
_30s.GetLastN(nums, 3); // { 3, 4, 5 }