Reference variables allow arguments to be passed by

Reference

Explanation:

The Reference type variable is such type of variable in C# that holds the reference of memory address instead of value. Examples for reference type are classes, interfaces, delegates and arrays.

We can pass parameters to the method by reference using ref keyword

It’s mandatory to initialize the variable value before we pass it as an argument to the method in c#

For example,

int x = 10;  // Variable need to be initialized

Add(ref x); // method call

If you pass parameters by reference in method definition, any changes made to it affect the other variable in method call.

Here's a sample program:

using System;

namespace ConsoleApplication

{

   public class Test

   {

       public static void Main()

       {

           int i = 10;

           Console.WriteLine("i=" + i);

           Add(ref i);

           Console.WriteLine("i=" + i);

           Console.ReadLine();

       }

       public static void Add( ref int j)

       {

           j = j + 10;

           Console.WriteLine("j="+j);

       }

   }

}

Output:

i=10

j=20

i=20

answer: internal fragmentation is the difference between the (fixed) size of a memory hole and the data within in that memory. for example, if a 1,024 byte block of memory holds 800 bytes of data, then the 224 bytes difference is considered lost to internal fragmentation.

external fragmentation occurs when the sum of memory fragments is large enough to satisfy a request, but the holes are non-contiguous and the request cannot be satisfied. this can occur when memory is dynamically allocated and freed.

explanation:

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