What are LINQ Last(), and LastOrDefault() functions?

Question

Ashutosh Kumar Verma · Answer

Last() vs LastOrDefault() in LINQ (C#)
Last() and LastOrDefault() both retrieve the last element from a collection, but they behave differently when no matching element is found.
and 
Last()
Returns the last element in the collection that matches a given condition.Throws an exception (InvalidOperationException) if no matching element is found.
Example-
using System;
using System.Linq;
using System.Collections.Generic;
class Program
{
   static void Main()
   {
       Listandlt;intandgt; numbers = new Listandlt;intandgt; { 3, 7, 8, 10, 15 };
       int lastEven = numbers.Last(n =andgt; n % 2 == 0);
       Console.WriteLine("Last Even Number: " + lastEven);
       // Output: Last Even Number: 10
   }
}
and 
and 
LastOrDefault()
Returns the last matching element, or the default value (null for reference types, 0 for numeric types) if no element is found.Does not throw an exception when no element matches.
Example-and 
Finding Last Even Number, with Default Handling
using System;
using System.Linq;
using System.Collections.Generic;
class Program
{
   static void Main()
   {
       Listandlt;intandgt; numbers = new Listandlt;intandgt; { 3, 7, 8, 10, 15 };
       int lastEven = numbers.LastOrDefault(n =andgt; n % 2 == 0);
       Console.WriteLine("Last Even Number: " + lastEven);
       // Output: Last Even Number: 10 (if present) or 0 (if no match)
       // with string
       Listandlt;stringandgt; names = new Listandlt;stringandgt; { "Alice", "Bob", "Charlie" };
       string result = names.LastOrDefault(n =andgt; n.StartsWith("Z"));
       Console.WriteLine(result == null ? "No match found" : result);
       // Output: No match found
   }
}
When to use what?
Use Last() when you are sure that at least one matching element exists.Use LastOrDefault() when no matching element exists (to avoid exceptions).
and 
Also, Read: 
Explain First(), FirstOrDefault() function in LINQ with C#
and

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What are LINQ Last(), and LastOrDefault() functions?

Amrith Chandran

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1 Answers

Last() vs LastOrDefault() in LINQ (C#)

Last()

LastOrDefault()

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