CSE240 Lecture 02

Introduction to Programming Languages
History of Programming Languages, Paradigms, and Features
(201701)

Transcript

1. jgs
   CSE 240
   Introduction to Programming Languages
   Lecture 02: History of Programming Languages, Paradigms, and Features
   Dr. Javier Gonzalez-Sanchez
   javiergs@asu.edu
   javiergs.engineering.asu.edu | javiergs.com
   PERALTA 230U
   Office Hours: By appointment
   

   View Slide

2. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 2
   jgs
   Machine Language
   Hardware
   Machine Language
   

   View Slide

3. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 3
   jgs
   Programming Languages
   Machine language
   A program is a sequence of bytes (binary numbers) stored
   in memory. The CPU interprets the program in the
   specified order.
   1940
   00000001 00000011
   00000001 00000101
   00000010 00000010
   00000011 00000111
   

   View Slide

4. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 4
   jgs
   Programming Languages
   Assembly Language
   Use of letters and numbers (hexadecimal or decimal) led
   to programming becoming more sophisticated (e.g., Intel
   assembly, MIPS, and similar to a bytecode for Java).
   Requires a program (assembler) to translate assembly
   language to machine code
   1947
   LOD 3
   LOD 5
   OPR 2
   STO 7
   00000001 00000011
   00000001 00000101
   00000010 00000010
   00000011 00000111
   

   View Slide

5. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 5
   jgs
   Assembly Language
   Hardware
   Machine Language
   Assembly Language
   

   View Slide

6. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 6
   jgs
   Programming Languages
   High-level languages
   Higher level programming languages, such as Autocode,
   FORTRAN, COBOL, LISP, Scheme, and C.
   • Variables of different types (real, integer, array)
   • Procedures or functions
   • Control structures
   Requires a program (compiler) to translate to assembly language
   and a program (assembler) to translate it to machine code
   1952
   LOD 3
   LOD 5
   OPR 2
   STO 7
   x = 3 + 5;
   00000001 00000011
   00000001 00000101
   00000010 00000010
   00000011 00000111
   

   View Slide

7. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 7
   jgs
   Language Levels
   Hardware
   Machine Language
   Assembly Language
   High-Level Language
   C
   Fortran
   C++
   Java
   

   View Slide

8. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 8
   jgs
   Paradigms
   x = 2 + 3;
   do { }
   while(true) ;
   int x = 5;
   (= X (SUM 2 3))
   ( repeat 0 10)
   (5)
   x ß 2 + 3.
   for 1 to 10
   x := (number)5.
   What is
   the result of
   two plus three?
   

   View Slide

9. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 9
   jgs
   Paradigms
   § Basic assumptions, ways of thinking, and methodology
   § that are commonly accepted
   § by members of a group or community.
   

   View Slide

10. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 10
    jgs
    Paradigms
    

    View Slide

11. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 11
    jgs
    Paradigms
    

    View Slide

12. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 12
    jgs
    The Four Main Paradigms and their Features
    Imperative or Procedural Paradigm
    Key idea:
    Fully specified and fully controlled
    manipulation of named data in a step-wise
    fashion.
    Features:
    • Divide the program into reasonable sized
    pieces named functions or procedures or
    modules or subroutines…
    • Local and global variables
    • Data structures
    • Conditional and loop statements
    

    View Slide

13. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 13
    jgs
    The Four Main Paradigms and their Features
    Object-oriented Paradigm
    Key idea:
    encapsulation of data and
    functionality of the program in
    objects.
    Features:
    • Inheritance and polymorphism
    • Class vs Instance variables
    (static)
    • Public, private, protected
    

    View Slide

14. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 14
    jgs
    The Four Main Paradigms and their Features
    Functional Paradigm
    Key idea:
    Focus on higher level of abstraction (free
    from programming details)
    Features:
    • simpler semantics
    • closer to mathematical functions
    

    View Slide

15. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 15
    jgs
    The Four Main Paradigms and their Features
    Logic/Declarative Paradigm
    Key idea:
    A program is a set of facts about objects,
    rules about objects, and questions about
    the relations between objects.
    Features:
    • get rid of programming altogether.
    male(james1).
    male(charles1).
    female(catherine).
    female(elizabeth).
    parent(charles1, james1).
    parent(elizabeth, james1).
    parent(catherine, charles1).
    % Was George I
    % the parent of Charles I?
    parent(charles1, george1).
    % Who was Charles I's parent?
    parent(charles1,X).
    % Who were the children of
    % Charles I?
    parent(X,charles1).
    

    View Slide

16. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 16
    jgs
    Summary
    Time
    Abstraction Level – Hiding complexity
    50s 60s 70s 80s 90s 00s 10s
    Logic
    Programming
    e.g. Prolog
    Imperative/
    Procedural
    Programming
    e.g. C
    Object-Oriented
    Programming
    e.g. C++ and Java
    Functional
    Programming
    e.g. LISP
    

    View Slide

17. Javier Gonzalez-Sanchez | CSE240 | Fall 2021 | 17
    jgs
    Reference
    Read Textbook Chapter 1 (section 1.1)
    

    View Slide

18. jgs
    CSE 240 Introduction to Programming Languages
    Javier Gonzalez-Sanchez, Ph.D.
    javiergs@asu.edu
    Fall 2021
    Copyright. These slides can only be used as study material for the class CSE240 at Arizona State University.
    They cannot be distributed or used for another purpose.
    

    View Slide