1. C# Language & .NET Platform 9th Lecture
Pavel Ježek
Some of the slides are based on University of Linz .NET presentations.
© University of Linz, Institute for System Software, 2004
published under the Microsoft Curriculum License (

2. CLI Type System All types Value types Reference types Pointers
(allocated in-place [with exceptions])
Reference types
(allocated on managed heap)
Pointers
Structures
Enumerations
Classes (e.g. strings)
Interfaces
Arrays
Delegates
Simple types
(Int32, Int64, Double, Boolean, Char, …)
Nullables
User defined structures

3. Visibility class private struct private Visibility modifiers:
public Access is not restricted.
protected Access is limited to the containing class or types derived from the containing class.
internal Access is limited to the current assembly.
protected internal Access is limited to the current assembly or types derived from the containing class.
private Access is limited to the containing type.
Default visibility in:
enum public
class private
interface public
struct private

4. CLI Type System All types Value types Reference types Pointers
(allocated in-place [with exceptions])
Reference types
(allocated on managed heap)
Pointers
Structures
Enumerations
Classes (e.g. strings)
Interfaces
Arrays
Delegates
Simple types
(Int32, Int64, Double, Boolean, Char, …)
Nullables
User defined structures

5. Parameters - "call by value"
value parameters (input parameters)
void Inc(int x) {x = x + 1;}
void f() {
int val = 3;
Inc(val); // val == 3 }
- "call by value"
- formal parameter is a copy of the actual parameter
- actual parameter is an expression

6. Parameters - "call by value"
value parameters (input parameters)
void Inc(int x) {x = x + 1;}
void f() {
int val = 3;
Inc(val); // val == 3 }
- "call by value"
- formal parameter is a copy of the actual parameter
- actual parameter is an expression
- "call by reference"
- formal parameter is an alias for the
actual parameter
(address of actual parameter is passed)
- actual parameter must be a variable
ref parameters (transient parameters)
void Inc(ref int x) { x = x + 1; }
void f() {
int val = 3;
Inc(ref val); // val == 4 }