C# Enumerable SingleOrDefault(IEnumerable, Func)
Description
Returns the only element of a sequence that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition.
Syntax
public static TSource SingleOrDefault<TSource>(
this IEnumerable<TSource> source,
Func<TSource, bool> predicate
)
Parameters
TSource
- The type of the elements of source.source
- An IEnumerableto return a single element from. predicate
- A function to test an element for a condition.
Example
The following code example demonstrates how to use SingleOrDefault to select the only element of an array that satisfies a condition.
/* w w w. j a v a 2 s .c o m*/
using System;
using System.Linq;
using System.Collections.Generic;
public class MainClass{
public static void Main(String[] argv){
string[] fruits = { "apple", "banana", "mango", };
string fruit1 = fruits.SingleOrDefault(fruit => fruit.Length > 2);
Console.WriteLine(fruit1);
string fruit2 = fruits.SingleOrDefault(fruit => fruit.Length > 15);
Console.WriteLine( String.IsNullOrEmpty(fruit2) ? "No such string!" : fruit2);
}
}