This post will discuss how to determine whether a list is empty in C#. The solution should return true if the list contains any elements; otherwise, false.
1. Using Enumerable.Any[] method [System.Linq]
To determine whether a list contains any elements, we can use the Enumerable.Any[] method. The following example demonstrates this use of Any.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | using System; using System.Collections.Generic; using System.Linq; public class Example { public static bool IsEmpty[List list] { if [list == null] { return true; } return !list.Any[]; } public static void Main[] { List list = new List[]; bool isEmpty = IsEmpty[list]; if [isEmpty] { Console.WriteLine["List is Empty"]; } else { Console.WriteLine["List contains elements"]; } } } /* Output: List is Empty */ |
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2. Using Enumerable.FirstOrDefault[] method [System.Linq]
The Enumerable.FirstOrDefault[] method returns the first element of a sequence. If no elements are found, FirstOrDefault returns a default value. We can use this to check for an empty list as follows:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 | using System; using System.Linq; using System.Collections.Generic; public class Example { public static bool IsEmpty[List list] { if [list == null] { return true; } return list.FirstOrDefault[] != null; } public static void Main[] { List list = new List[]; bool isEmpty = IsEmpty[list]; if [isEmpty] { Console.WriteLine["List is Empty"]; } else { Console.WriteLine["List contains elements"]; } } } /* Output: List is Empty */ |
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3. Using Enumerable.Count[] method [System.Linq]
Another approach is to use the Enumerable.Count[] method, which returns the total number of elements in a sequence.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 | using System; using System.Collections.Generic; public class Example { public static bool IsEmpty[List list] { if [list == null] { return true; } return list.Count == 0; } public static void Main[] { List list = new List[]; bool isEmpty = IsEmpty[list]; if [isEmpty] { Console.WriteLine["List is Empty"]; } else { Console.WriteLine["List contains elements"]; } } } /* Output: List is Empty */ |
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Thats all about determining whether a list is empty in C#.