C

1
C

• Amy Broom
• Hossam Ragaban
• Randal Rollings

Fall 2003
2
History

• The history of C begins early in 1970s when C
  was invented in which UNIX was written. But C had
  some drawbacks. The power that C affords the
  programmer makes it easy for him to blunder. For
  example, it allows the programmer to directly
  allocate memory and permits him to deallocate
  this memory.
• Then came C in the 1980s, who like its
  predecessor took the world by a storm. Despite it
  being object-oriented C had some problems.
  Veteran programmers often had problems migrating
  from C (structured) to C ( object-oriented )
  because effective C programming requires a
  completely new mindset. 

3
More History

• Sun created Java. They were motivated with the
  World Wide Web. They sought a single environment
  that would target multiple platforms. Programs in
  Java are not compiled to machine code, but
  instead to an intermediate language or bytecode
  that can be executed on any computer equipped
  with a suitable interpreter program (The Java
  Runtime). 
• Today, Microsoft unveils an alternative strategy
  for bringing the development and web worlds
  together and online with .NET. Because all .NET
  languages compile to a common bytecode, a
  developer can program in whichever language he
  wants and share his works with other developers
  using other .NET languages. 

4
Even More History

• In June 2000, Microsoft announced both the .NET
  platform and a
• new programming language called C. C is a
  strongly-typed
• object-oriented language designed to give the
  optimum blend of
• simplicity, expressiveness, and performance. The
  .NET platform
• is centered around a Common Language Runtime
  (similar to a
• JVM) and a set of libraries which can be
  exploited by a wide
• variety of languages which are able to work
  together by all
• compiling to an intermediate language (IL). C
  and .NET are a
• little symbiotic some features of C are there
  to work well with
• .NET, and some features of .NET are there to work
  well with C
• (though .NET aims to work well with many
  languages). The C
• language was built with the hindsight of many
  languages, but
• most notably Java and C. It was co-authored by
  Anders
• Hejlsberg (who is famous for the design of the
  Delphi language),
• and Scott Wiltamuth.

5
Common Language Runtime

• The CLR serves as an execution engine for
  applications.
• Every byte of code that you write for the
  framework runs in the CLR.
• CLR consists of instructions written in
  CIL(common intermediate language-pseudo-machine
  language). CIL instructions are just-in-time and
  compiled into native machine code at run time.
• A given method is compiled only once-the first
  time it is called-and thereafter cached in memory
  so it can be executed again without delay.

6
Advantages

• This robust development package, which uses the
  component
• oriented C development language, offers
  beginning and
• intermediate developers with C or Java
  experience a modern
• language and environment for creating
  next-generation software.
• Visual C .NET 2003 delivers superior
  functionality for
• streamlining business processes, including
• Rapid design, development, and deployment support
  for creating and consuming Web services.
• Form designers and visual controls for creating
  rich Windows-based applications.
• Authoring tools and services for building
  powerful Microsoft .NET server-based solutions.
• Migration tools for converting Java-based
  projects to the Microsoft .NET development
  environment

7
Advantages

• With Visual C .NET 2003, developers can
• build solutions for a wide range of clients
• including Windows, the Web, and mobile or
• embedded devices. Using this elegant
• programming language and its tools,
• developers can leverage their existing C
• and Java-language skills and knowledge to be
• successful in the .NET environment.

8
Improvements

• C offers significant improvements including
  unified type system, powerful new language
  constructs which are easily understood by
  developers, and unsafe code of maximum
  developer control. The language provides
  inherent support for properties, indexers,
  versioning, operator overloading, delegates, and
  custom attributes.

9
C and Java Similarities

• Compiles into machine-independent
  language-independent code which runs in a managed
  execution environment.
• Garbage Collection coupled with the elimination
  of pointers (in C restricted use is permitted
  within code marked unsafe)
• No header files, all code scoped to packages or
  assemblies, no problems declaring one class
  before another with circular dependencies
• Classes all descend from object and must be
  allocated on the heap with new keyword
• Thread support by putting a lock on objects when
  entering code marked as locked/synchronized
• Interfaces, with multiple-inheritance of
  interfaces, single inheritance of implementations
  
• Inner classes

10
C and Java Similarities cont.

• No concept of inheriting a class with a specified
  access level
• No global functions or constants, everything
  belongs to a class
• Arrays and strings with lengths built-in and
  bounds checking
• The "." operator is always used, no more -gt,
  operators
• null and boolean/bool are keywords
• All values are initialized before use
• Try Blocks can have a finally clause

11
Main Features

• Pointers are missing in C.
• Unsafe operations such as direct memory
  manipulation are not allowed.
• In C there is no usage of "" or "-gt"
  operators.
• Since its on .NET, it inherits the features of
  automatic memory management and garbage
  collection.
• Integer values of 0 and 1 are no longer accepted
  as boolean values.Boolean values are pure true or
  false values in C so no more errors of
  ""operator and ""operator. "" is used for
  comparison operation and "" is used for
  assignment operation.

12
Testing and Debugging

• Testing and debugging tools are of the
  languages features providing a powerful remote
  and multi-language debugger that allows
  developers to test applications and build
  reliable multi-tier solutions that span process
  boundaries and are written in multiple
  programming languages.

13
Delegates

• A delegate can be thought of as a type-safe
  object-
• oriented function pointer, which is able to hold
  multiple
• methods rather than just one. Delegates handle
• problems which would be solved with function
  pointers
• in C, and interfaces in Java. It improves on
  the
• function pointer approach by being type safe and
  being
• able to hold multiple methods. It improves on the
  
• interface approach by allowing the invocation of
  a
• method without the need for inner-class adapters
  or
• extra code to handle multiple-method invocations.

14
Events

• C provides direct support for events. Although
  event
• handling has been a fundamental part of
  programming
• since programming began, there has been
  surprisingly
• little effort made by most languages to formalize
  this
• concept. If you look at how today's mainstream
• frameworks handle events, we've got examples like
  
• Delphi's function pointers (called closures),
  Java's inner
• class adaptors, and of course, the Windows API's
  message
• system. C uses delegates along with the event
  keyword
• to provide a very clean solution to event
  handling.

15
Properties

• Properties will be a familiar concept to Delphi
  and Visual Basic users. The motivation is for the
  language to formalize the concept of
  getter/setter methods, which is an extensively
  used pattern, particularly in RAD (Rapid
  Application Development) tools.
• This is typical code you might write in Java or
  C
• foo.setSize (getSize () 1)
• label.getFont().setBold (true)
• The same code you would write like this in C
• foo.size
• label.font.bold true

16
Polymorphism

• Virtual methods allow object oriented
• languages to express polymorphism. This
• means a derived class can write a method
• with the same signature as a method in its
• base class, and the base class will call the
• derived class's method. By default in Java, all
• methods are virtual. In C, like C, the
• virtual keyword must be used so that the
• method will be called by the base class.

17
Foreach Statement

• C provides a shorthand for for-loops
• In Java or C
• for (int i 0 i lt array.length i)...
• In C
• foreach (int i in array)...

18
Bibliography

• http//msdn.microsoft.com/vcsharp/productinfo/feat
  ures/default.aspx
• http//genamics.com/developer/csharp_comparative.h
  tm
• http//www.csharphelp.com/archives/archive55.html
• http//www.funducode.com/csharp/basics/basics1.htm
  
• http//msdn.microsoft.com/vcsharp/productinfo/over
  view/default.aspx