Internal & Protected Internal

Here's a simple example to illustrate the difference between the two.

First compile the following as a dll called testdll.dll:

// testdll.cs

public class MyClass

{

internal int MyInt = 3;

protected internal int MyOtherInt = 4;

}

public class YourClass

{

public int GetMyInt()

{

MyClass mc = new MyClass();

return mc.MyInt; // OK as MyInt is internal

}

public int GetMyOtherInt()

{

MyClass mc = new MyClass();

return mc.MyOtherInt; // OK as MyOtherInt is internal as well as protected

}

Now, compile the following as an exe called testexe.exe, after first adding a reference to testdll.dll:

// testexe.cs

using System;

class Test

{

static void Main()

{

OurClass oc = new OurClass();

Console.WriteLine(oc.GetMyOtherInt()); // 4

Console.ReadKey();

}

class OurClass : MyClass // inherits from MyClass

{

/* GetMyInt doesn't compile because MyInt is internal and so only accessible in its own assembly

public int GetMyInt()

{

return MyInt; // Not OK as MyInt is internal

}

public int GetMyOtherInt()

{

return MyOtherInt; // OK as MyOtherInt is protected as well as internal

}

Notice that 'protected internal' in C# means 'protected OR internal'.

The CLR also has the concept of 'protected AND internal' which means that the member is only accessible from within its class or within a derived class in the same assembly. It's never accessible from a different assembly.

However, neither C# nor VB.Net supports protected AND internal (however C++/CLI and CIL do) so this is academic unless you're using reflection to create a class dynamically.

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Vulpes15y ago
Here's a simple example to illustrate the difference between the two.

First compile the following as a dll called testdll.dll:

// testdll.cs

public class MyClass
{
internal int MyInt = 3;

protected internal int MyOtherInt = 4;
}

public class YourClass
{
public int GetMyInt()
{
MyClass mc = new MyClass();
return mc.MyInt; // OK as MyInt is internal
}

public int GetMyOtherInt()
{
MyClass mc = new MyClass();
return mc.MyOtherInt; // OK as MyOtherInt is internal as well as protected
}
}

Now, compile the following as an exe called testexe.exe, after first adding a reference to testdll.dll:

// testexe.cs

using System;

class Test
{
static void Main()
{
OurClass oc = new OurClass();
Console.WriteLine(oc.GetMyOtherInt()); // 4
Console.ReadKey();
}
}

class OurClass : MyClass // inherits from MyClass
{
/* GetMyInt doesn't compile because MyInt is internal and so only accessible in its own assembly

public int GetMyInt()
{
return MyInt; // Not OK as MyInt is internal
}

*/

public int GetMyOtherInt()
{
return MyOtherInt; // OK as MyOtherInt is protected as well as internal
}
}

Notice that 'protected internal' in C# means 'protected OR internal'.

The CLR also has the concept of 'protected AND internal' which means that the member is only accessible from within its class or within a derived class in the same assembly. It's never accessible from a different assembly.

However, neither C# nor VB.Net supports protected AND internal (however C++/CLI and CIL do) so this is academic unless you're using reflection to create a class dynamically.
0
Gomathi Palaniswamy15y ago

Internal - The internal can be accessed from same name assembly but not by some other assembly like public.
Protected internal - The protected internal can be accessed by same assembly and derived assembly.
0
Mayur Gujrathi15y ago
refer this
0