List IsNullOrEmpty C#

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.

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using System;
using System.Collections.Generic;
using System.Linq;
public class Example
{
public static bool IsEmpty<T>(List<T> list)
{
if (list == null) {
return true;
}
return !list.Any();
}
public static void Main()
{
List<int> list = new List<int>();
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:

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using System;
using System.Linq;
using System.Collections.Generic;
public class Example
{
public static bool IsEmpty<T>(List<T> list)
{
if (list == null) {
return true;
}
return list.FirstOrDefault() != null;
}
public static void Main()
{
List<int> list = new List<int>();
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.

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using System;
using System.Collections.Generic;
public class Example
{
public static bool IsEmpty<T>(List<T> list)
{
if (list == null) {
return true;
}
return list.Count == 0;
}
public static void Main()
{
List<int> list = new List<int>();
bool isEmpty = IsEmpty(list);
if (isEmpty) {
Console.WriteLine("List is Empty");
}
else {
Console.WriteLine("List contains elements");
}
}
}
/*
Output: List is Empty
*/

DownloadRun Code

Thats all about determining whether a list is empty in C#.