7 Mayıs 2018 Pazartesi

ref Anahtar Kelimesi - Return Type

C# 7 ile referans dönmek mümkün.Açıklaması şöyle.
You can only return refs that are “safe to return”: Ones that were passed to you, and ones that point into fields in objects.
array dönülebilir. Açıklaması şöyle.
Returning a local int variable instead of an array is not possible. int is a value type, and thus the variable gets out of scope at the end of the method, and thus a reference to it cannot be returned. That’s different with an array. An array is a reference type, and the array is allocated on the heap. An int within the array can be returned with the ref keyword.
Örnek - int
Şöyle yaparız.
public ref int Find(int number, int[] numbers)
  for (int i = 0; i < numbers.Length; i++)
    if (numbers[i] == number)
      return ref numbers[i]; // return the storage location, not the value
  throw new IndexOutOfRangeException($"{nameof(number)} not found");
Örnek - array
Şöyle yaparız.
public ref string Find (int index)
  string[] array = { "a", "b", "c", "d" };
  return ref array[index]; 
Örnek - struct
Şöyle yaparız.
// This size is 128 bytes, which is 2 or 4x larger than the size of a reference
public struct Coord                                 
    public long X, Y;

private Coord myCoord;

// This will return the Coord by value, meaning copying the full 128 bytes
public Coord GetCoordValue() => myCoord;          

// This will return the Coord by reference, meaning copying only 32 or 64 bytes
public ref readonly Coord GetCoordRef() => ref myCoord;      

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