What are Local functions in C# 7.0?

Local functions are private methods of a type that are nested in another member. They can only be called from their containing member.

Local functions can be declared in and called from −

• Methods, especially iterator methods and async methods

• Constructors

• Property accessors

• Event accessors

• Anonymous methods

• Lambda expressions

• Finalizers

• Other local functions

Example 1

class Program{
   public static void Main(){
      void addTwoNumbers(int a, int b){
         System.Console.WriteLine(a + b);
      }
      addTwoNumbers(1, 2);
      Console.ReadLine();
   }
}

Output

3

Example 2

class Program{
   public static void Main(){
      void addTwoNumbers(int a, int b, out int c){
         c = a + b;
      }
      addTwoNumbers(1, 2, out int c);
      System.Console.WriteLine(c);
      Console.ReadLine();
   }
}

Output

3