Simple Procedural, BlockStructured Procedural, and ObjectOriented Languages

1
Simple Procedural, Block-Structured Procedural,
and Object-Oriented Languages

• In brief very.

2
Simple Procedural Languages

• Such languages consist of a series of procedures
  (or subprograms or functions or subroutines) that
  execute when called
• Each procedure consists of a sequence of
  statements, where each statement manipulates data
  that may either be local to the procedure, a
  parameter passed in from the calling procedure,
  or defined globally
• Local data for each procedure are stored in an
  activation record associated with that procedure
• Scope rules are minimal
• Execution efficiency is a primary focus

3
Simple Procedural Languages

• Representative languages
• FORTRAN
• Widely used for scientific and engineering
  computation
• C
• Designed for systems progamming
• COBOL
• Still used in business applications

4
Block-Structured Procedural Languages

• Designed for programmer flexibility rather than
  run-time performance
• Utilize activation records
• Employ scope rules and nested block structure for
  storing and accessing data
• May execute somewhat less efficiently than
  languages such as FORTRAN or C

5
Block-Structured Procedural Languages

• Representative languages
• Pascal
• (Ada
• Supports data encapsulation
• Thus it may be grouped with object-based
  languages
• )

6
Object-Oriented Languages

• Provide data abstraction capabilities
• The data representation of a specific data type
• The subprograms that provide the operations for
  that type
• Provide inheritance capabilities
• Provide dynamic binding capabilities
• Therefore, they permit object-oriented
  programming

7
Object-Oriented Languages

• Categories of languages that support OOP
• OOP support is added to an existing language
• C (also supports procedural and
  data-orientedprogramming)
• Ada 95 (also supports procedural and
  data-orientedprogramming)
• CLOS (COMMON LISP Object System also supports
  functional programming)
• Scheme (also supports functional programming)
• Support OOP, but have the same appearance and use
  the basic structure of earlier
  imperative languages
• Eiffel (not based directly on any previous
  language)
• Java (based on C)

8
Object-Oriented Languages

• Categories of languages that support OOP
• Pure OOP languages
• Smalltalk