C# Enumerable FirstOrDefault(IEnumerable)
Description
Returns the first element of a sequence, or a default value if the sequence contains no elements.
Syntax
public static TSource FirstOrDefault<TSource>(
this IEnumerable<TSource> source
)
Parameters
TSource- The type of the elements of source.source- The IEnumerableto return the first element of.
Example
The following code example demonstrates how to use FirstOrDefault on an empty array.
/* www .j a v a 2 s . co m*/
using System;
using System.Linq;
using System.Collections.Generic;
public class MainClass{
public static void Main(String[] argv){
int[] numbers = { };
int first = numbers.FirstOrDefault();
Console.WriteLine(first);
List<int> months = new List<int> { };
int firstMonth1 = months.FirstOrDefault();
if (firstMonth1 == 0)
{
firstMonth1 = 1;
}
Console.WriteLine(firstMonth1);
int firstMonth2 = months.DefaultIfEmpty(1).First();
Console.WriteLine(firstMonth2);
}
}
The code above generates the following result.
