C Programming Language

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C Programming Language

• Presented by Shahibullah Ithnin
• WGA 050035

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Part I Introduction of C

• Developed by Bjourne Stroustrup in 1983 as
  enhancement from C (fast and reliable)
• Design goal for programmer to create a good
  program which be produced easier and more
  pleasant.
• Application area multimedia (Adobe), OS
  (Apple), animation software (Maya), browser
  (Mozilla) handphone (Nokia) etc.

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Part I Introduction of C (cont)

• Programming Paradigm
• Procedural instruction telling computer
  step-by-step what to do like ifelse and
  dowhile.
• Modular large program can be break into small
  modules for easily testing and run like
  functions
• Object-oriented properties, operations and
  behaviors in common from previous project can be
  apply to new project with inheritance.
• Generic reused data type in a variety of
  situations with polymorphism.

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Part I Introduction of C (cont)

• Features
• Operators performs Boolean arithmetic on values
  and strings of text.
• Preprocessor process input data to produce
  output used as next input to another program.
• Template can be used to produce conditional
  compilation. Templates are a tool for static
  polymorphism and generic programming.
• Objects object-oriented features such as
  classes, abstraction, encapsulation, inheritance,
  polymorphism.

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Part I Introduction of C (cont)

• Claims for security, portability, efficiency and
  extensibility/maintainability
• Security with poor coding practice, its easy
  to write data outside the allocated buffer in
  memory. When the vulnerability is exploited by
  bugs makes the program crashed (buffer overrun).
• Portability easy to compile with different
  compiler and platform due to language standard,
  thus able to swift from one project to another.

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Part I Introduction of C (cont)

• Claims for security, portability, efficiency and
  extensibility/maintainability (cont )
• Efficiency by choosing right compiler with the
  support of OOP principal makes it run faster,
  less space and processor power consumption.
• Extensibility/maintainability with inheritance
  and polymorphism, its easy to maintain the
  development of new codes which readily to be
  modified for new requirements.

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Part I Introduction of C (cont)

• The compilation model
• There are many compilers for C around and gcc
  is the most popular and available for many
  different platforms. But for Microsoft Windows
  users, they would be familiar with the Borland
  bcc compiler.
• Next slide will show the general descriptions for
  the gcc C compilers.

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Part I Introduction of C (cont)
Figure 1 gcc compilation model for C
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Part II Description of Language

• Why C, C and Java
• C predecessor of C and adding more advance
  features to develop C class, operator
  overloading and many more.
• Java developed from C by simplifying and
  removing some features such as pointers, operator
  overloading, enum and many more.
• Comparison included
• Scalar data (enumerations)
• Composite object (pointers)

• Structured object (arrays)
• Abstract data (classes)

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Scalar Data Object enum

• Scalar data object enum is used to assign a
  static value for variables in C
• The comparison is
• C uses define
• C uses enum
• Java uses class

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Composite Object pointers

• A pointer is a variable which contains the
  address in memory of another variable in C and
  C
• The difference is
• C uses malloc ()
• C uses new
• Java has no pointer

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Structured Object array

• Arrays is used to store several to many that are
  of the same type and logically related to each
  other.
• Both C, C and Java share the same syntax to
  create arrays

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Structured Object array (cont )
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Abstract Data Type classes

• Classes provide access to members of a class with
  public, private and protected.
• The difference is
• C does not have class.
• C declare the protection level
• public
• void setValues ()
• int displayArea ()
• Java declares the protection level
• public void setLength()
• public int displayArea()

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Abstract Data Type classes (cont )
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Abstract Data Type classes (cont )
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Part III Final Evaluation

• Basic to agree/disagree with any claim for
  security, portability, efficiency,
  maintainability
• Security /GS compiler generates code that
  detects buffer overrun during run-time and close
  the vulnerability without affecting performance.
  It also protects vulnerable parameter from being
  passed into a function to be overwritten by
  buffer overrun. Thus, it will enhance the code
  security and robustness.

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Part III Final Evaluation (cont )

• Efficiency object-oriented principles and the
  choosing the right compiler enable program to
  perform better.
• Portability however, the program might perform
  inefficient or slow when running in different
  platform due to some problems such as
  incompatible compiler version.
• Maintainability to solve this, the code should
  always be modifiable to fit into the different
  requirements and environments.
• Sometimes, when editing the code for enhancement
  without proper testing could inject bugs (poor
  coding practice)
• Thus, the expenses of maintainability to fulfill
  new requirements always cost for more budget.
• Conclusion, if the goal is to have efficient
  programs, we should compromise on the
  portability. Otherwise, maintainability always
  comes first with high cost to support the
  portability.

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Part III Final Evaluation (cont )

• Difficulty in C How to use pointer and
  reference?

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Part III Final Evaluation (cont )

• Programming environment rating
• Preferred compiler gcc (good)
• Easy to do detection and reporting on some
  obvious error such as misspelled keywords or
  omitted semi-colon.
• Preferred language in future
• It has useful features to write portable,
  efficient and easy-to-use libraries.
• For instance, in developing a complex system, a
  programmer might use variety of popular scripting
  language for writing interfaces, SQL for database
  queries, Java for network programming or
  Postscript to communicate with a printer.
• In these scenarios, C is able to well-suited
  tying them to work together. It has features
  specifically for calling libraries written in
  other languages to make them easy to be connected
  with C.

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Main Reference

• www.wikipedia.com
• www.answer.com
• www.cplusplus.com
• http//java.sun.com
• www.thescripts.com