Principles of

Programming Languages
UNIT I - Fundamentals of Programming
 Importance of Studying Programming Languages
 History of Programming Languages
 Impact of Programming Paradigms
 Role of Programming Languages
 Programming Environments
 Impact of Machine Architectures: The operation of a computer,
Virtual Computers and Binding Times.
UNIT I - Fundamentals of Programming
Programming paradigms-
 Introduction to programming paradigms
 Introduction to four main Programming paradigms

Procedural
Object Oriented
Functional
Logic and Rule based
Importance of Studying Programming Languages

Computers aren't very smart

Ask the computer to draw a picture of

bird…

Will it draw?
Importance of Studying Programming Languages

Computers are bad at understanding things

Importance of Studying Programming Languages

Computers cannot understand English

Functional View of a Computer

Output
CPU Devices
Input
Devices
Main Secondary
Memory Memory
 Functional View of a Computer
▪ Humans interact with computers via Input and
E.g., Keyboard Output (IO) devices
and mouse E.g., Monitor

▪ Information from Input devices are processed by

Output
Input the CPU and may be shuffled off to the main or
secondary memory Devices
Devices

▪ When information need to be displayed, the CPU

sends them to one or more Output devices
• A program is just a sequence of instructions telling the computer what to
do
• Obviously, we need to provide these instructions in a language that
computers can understand
• We refer to this kind of a language as a programming language
• Python, Java, C and C++ are examples of programming languages
• Every structure in a programming language has an exact form (i.e., syntax)
and a precise meaning (i.e., semantic)
Six Reasons to Learn Programming Languages
 Reason 1:

To improve your ability to develop effective algorithms

● The depth at which people can think is heavily influenced by the
expressive power of their language.
● It is difficult for people to conceptualize structures that they cannot
describe, verbally or in writing.
 Reason 2
To improve your use of your existing programming language
● Many professional programmers have a limited formal education in
computer science, limited to a small number of programming languages.
● They are more likely to use languages with which they are most
comfortable than the most suitable one for a particular job.
 Reason 3
● Computer science is consider as a young discipline and most software
technologies (design methodology, software development, and
programming languages) are not yet mature. Therefore, they are still
evolving.
● The understanding of programming language design and implementation
makes it easier to learn new languages.
 Reason 4
● It is often necessary to learn about language implementation; it can lead
to a better understanding of why the language was designed the way that
it was.
● Fixing some bugs requires an understanding of implementation issues.
 Reason 4
● Some languages are better for some jobs than others.
○ (i) FORTRAN and APL for calculations, COBOL and RPG for report
generation, LISP and PROLOG for AI, etc.
● Improve your use of existing programming language
● By understanding how features are implemented, you can make more
efficient use of them.
 Reason 5
● To improve your use of existing programming language
● By understanding how features are implemented, you can make more
efficient use of them.
● Examples:
● Creating arrays, strings, lists, records.
● Using recursions, object classes, etc.
 Reason 6
● Designing a new language require prior knowledge of previous one to
make it effective, efficient and convenient to users.
● The previous knowledge as well as concepts are usual to design a new
language irrespective of their work domains.
 History of Programming languages

● Development of Early Language

● Evolution of Software Architecture
● Application Domains
 History of Programming languages
● 1951- 55: Experimental use of expression compilers.
● 1956- 60: FORTRAN, COBOL, LISP, Algol 60.
● 1961- 65: APL notation, Algol 60 (revised), SNOBOL, CPL.
● 1966- 70: APL, SNOBOL 4, FORTRAN 66, BASIC, SIMULA, Algol
68, Algol-W, BCPL.
● 1971- 75: Pascal, PL/1 (Standard), C, Scheme, Prolog.
● 1976- 80: Smalltalk, Ada, FORTRAN 77, ML, C++.
 History of Programming languages
● 1981- 85: Smalltalk-80, Prolog, Ada 83.
● 1986- 90: SML, Haskell.
● 1991- 95: Ada 95, TCL, Perl.
● 1996- 2000: Java.
● 2000- 05: C#, Python, Ruby, Scala.
Development of Early Language
 Development of Early Language
● Numerically based languages
Computing mathematical expressions
FORTRAN, Algol, Pascal, PL/1, BASIC, C, C++
● Business languages
COBOL (Common Business Oriented Language)
English-like notation
 Development of Early Language
● Artificial intelligence languages
Tree search; Rule-based paradigm
LISP (LISt Processing)
PROLOG (PROgramming in LOGic)
● System languages :C, C++
● Script languages: AWK, Perl, TCL/TK
● Web programming: HTML, XML, Java, Microsoft *.NET family
Evolution of Software Architecture
 Evolution of Software Architecture
● Mainframe Era
○ Batch processing (batches of files)
○ Interactive processing (time sharing)
● Effects on language design
○ File I/O in batch processing
○ Error handling in batch processing
○ Time constraints in interactive processing
 Evolution of Software Architecture
● Personal Computer
○ Interactive processing
○ Embedded system environments
Effects on language design
○ No need for time sharing
○ Good interactive graphics
○ Non-standard I/O devices for embedded systems
 Evolution of Software Architecture
● Networking Era
○ Client-server model of computing
○ Server: a program that provides information
○ Client - a program that requests information
Effects on language design
○ Interaction between the client and server programs
○ Active web pages, Security issues, Performance
 Application Domain
● Business Processing
● Scientific
● System
● Artificial Intelligence
● Publishing
● Process
 Impact of Programming Paradigms
This Causes Impact on

● Way Programmers are Solving the Program

● Challenge to Describe Needs of the Stakeholders and Solution
Requirements
● Provided an Underlying Model to Verify and Validate the
Program in a Reliable Manner.
● Minimize the Design Errors
● Provides Variety of Techniques to manage Complexity.
● How to Design a Software
Influences in Design of Programming Languages
Some influences on the development of Programming Languages
Role of Programming Languages
Good Language
 Clarity, Simplicity And Unity
● A Programming language provides both a conceptual framework for
Algorithm planning and means of expressing them.
● It should provide a clear, simple and unified set of concepts that can be used
as primitives in developing algorithms.
● It should have
• It has minimum number of different concepts
• with Rules for their combination being
• simple and regular.
This attribute is called conceptual integrity.
 Orthogonality
● It is one of the most important feature of PL orthogonality is the property that
means " Changing A does not change B".
● If I take Real world example of an orthogonal system Would be a radio, where
changing the station does not change the volume and vice versa.
● When the features of a language are orthogonal, language is easier to learn
and programs are easier to write because only few exceptions and special
cases to be remembered.
 Naturalness for the application
Language should provide appropriate data structures, operations, control structures and
proper natural syntax.

Support for Abstraction

There is always found that a substantial gap remaining between the abstract data structure
and operations that characterize the solution to a problem and their particular data
structure and operations built into a language.
 Programming Environment
● An appropriate programming environment adds an extra utility and make
language to be implemented easily like
● The availability of- Reliable- Efficient - Well documentation Speeding up
creation and testing by-special Editors- testing packages
● Facility- Maintaining and Modifying- Multi Version of program software
product.
Programming Environment
 Ease of program verification:- Reusability
● The reusability of program written in a language is always a central concern.
A program is checked by various testing technique like
● Formal verification method Desk checking Input output test checking.
● We verify the program by many more techniques.
● A language that makes program verification difficult maybe far more
troublesome to use.
● Simplicity of semantic and syntactic structure is a primary aspect that tends to
simplify program verification.
 Syntax and Semantics
● The syntax of programming language is what the program looks like.
● How statements declaration and other constructs are written
● The semantic of Pl is a meaning given to the various syntactic constructors.
Role of Programming Languages
 Language Paradigms

● Imperative language
● Applicative language
● Rule based language
● Object oriented language
 Imperative Languages
● Command driven or statement oriented
● The basic concept is machine state
● A program consists of sequences of statement
● Execution of each instruction causes the computer to change the value of one or
more location , to enter a new state.
● Syntax of such languages
Imperative Languages
● Many Widely used Languages C, C++,
FORTRAN, PL/I, Pascal , Ada, Small
Talk and COBOL support this model.
● Most of the all conventional languages
 Applicative Languages
● Programming language is to look at the function that the program represents
rather than just the state changes as the program executes, statement by
statement.
● Focus on the desired result rather than at the available data.
● What is the function that must be applied to the initial machine state by
accessing the initial set of variables and combining them in specific ways to
get an answer?
● The languages which emphasize this view are called applicative or functional
languages.
Applicative Languages

● LISP and ML are two functional

languages
 Rule based Languages
● Execute by checking for the presence of a certain enabling condition and,
when present, executing an appropriate action.
● The most common rule-based language is Prolog, also called a logic
programming
Rule based Languages
 Object Oriented Languages
● Complex data objects are built, then a limited set of functions are designed
to operate on those data.
● Complex objects are designed as extensions of simpler objects, inheriting
properties of the simpler object.
● The best of two of the other computational models.
○ By building concrete data objects, an object-oriented program gains
the efficiency of imperative languages.
○ By building classes of functions that use a restricted set of data
objects, we build the flexibility and reliability of the applicative model.
Generality of Computational Model
Role of Programming Languages
 Language standardization
● What describes a programming language?
● int i; i = (1 && 2) + 3 , Is it valid Statement in C?
● To have an answer to this we usually follow following
approaches (Next Slide)
 Language standardization
1. Read the definition in the language reference manual to
decide what the statement means.
2. Write a program on your local computer system to see
what happens.
3. Read the definition in the language standard.
 Language standardization
To address these concerns, most languages have standard definitions.
1. Proprietary standards.
a. These are definitions by the company that develops and owns the language.
b. Do not work for languages that have become popular and widely used.
c. Variations in implementations soon appear with many enhancements and
incompatibilities.
2. Consensus standards.
d. These are documents produced by organizations based on an agreement by the
relevant participants.
e. Consensus standards, or simply standards, are the major method to ensure
uniformity among several implementations of a language.
 Language standardization

Proprietary Consensus
HTML , C#, WWW

Need License No License

 Language standardization
To use standards effectively, we need to address three issues:
1. Timeliness : When do we standardize a language?
2. Conformance : What does it mean for a program to adhere to a
standard and for a compiler to compile a standard?
3. Obsolescence: When does a standard age, and how does it get
modified?
 Language standardization
To use standards effectively, we need to address three issues:
Timeliness : When do we standardize a language?
● One would like to standardize a language early enough so that there is
enough experience in using the language, yet not so late as to encourage
many incompatible implementations.
 Language standardization

To use standards effectively, we need to address three issues:

● Conformance : What does it mean for a program to adhere to a standard
and for a compiler to compile a standard?
● A program is conformant if it only uses features defined in the standard.
● A conforming compiler is one that, when given a conformant program,
produces an executable program that produces the correct output.
Role of Programming Languages
 Language Internationalization
To use standards effectively, we need to address three issues:
Obsolescence: When does a standard age, and how does it get modified?
● Standards have to be reviewed every 5 years and either be renewed or dropped.
● The 5-year cycle often gets stretched out somewhat, but the process is mostly
effective
● Problem with updating a standard is what to do with the existing collection of
programs written for the older standard
● most standards require backward compatibility; the new standard must include
older versions of the language.
 Language Internationalization
● Collating sequences : In what collating sequence should the characters be ordered?
○ Sorting. The position of non-Roman characters, such as A, @, B, 3, and others
s not uniformly defined and may have different interpretations in different
countries.
○ Case. Some languages like Japanese, Arabic, Hebrew, and Thai have no
uppercase—lowercase distinction.
○ Scanning direction. Most languages read from left to right, but others exist
(e.g., right to left, top to bottom).
 Language Internationalization
● Country-specific date formats.
11/26/02 in the United States is 26/11/02 in England; 26.11.02 in France; 26-XI-02
in Italy, etc.
● Country-specific time formats.
5:40 p.m. in the United States is 17:40 in Japan, 17.40 in Germany, 17h40 in
France,and so on.
 Language Internationalization
● Time zones.
○ Although the general rule is 1 hour of change for each 15 degrees of
longitude, it is more a guideline than a reality.
○ Time zones are generally an integral number of hours apart, but some vary by
15 or 30 minutes.
○ Time changes (e.g., daylight savings time in the United States and summer
time in Europe) do not occur uniformly around the world.
○ Translating local time into a worldwide standard time is nontrivial.
 Language Internationalization
● Ideographic systems.
Some written languages are not based on a small number of characters forming an
alphabet, but instead use large numbers of ideographs (e.g., Japanese, Chinese, and
Korean).
Often 16 bits might be needed to represent text in those languages.
● Currency.
Representation of currency (e.g., $, £, ¥) varies by country.
 Programming Environment

● Effects on Language Design

● Environment Frameworks
● Job Control and Process Languages
 Programming Environment-Effects on Language Design
● it is ordinarily desirable to have different programmers or programming groups
design, code, and test parts of a program before final assembly of all components into
a complete program.
● Language must be structured so that subprograms or other parts can be
separately compiled and executed, later merged without change into the final
program.
● Compiler may need information about other subprograms or shared data
○ The specification of the number, order, and type of parameters expected by
any subprogram
○ to determine the storage representation of the external variable
○ The definition of a data type that is defined externally but is used to declare
any local variable within the subprogram
 Programming Environment-Effects on Language Design

● Another aspect of separate compilation that affects language design

○ shared name
○ scoping rules
○ Inheritance
● Testing and debugging.
○ Execution trace features.
○ Breakpoints.
○ Assertions.
assert( X>0 and A=1) or (X=0 and A>B+10).
 Programming Environment- Environment Frameworks
● Support environment consists of infrastructure services called the environment
framework to manage development of Program.
● Supplies services such as a data repository, graphical user interface, security, and
communication services.
● Languages are sometimes designed to allow for easy access to these infrastructure
services.
 Programming Environment- Job Control and Process Languages

● Click and Execute Environment

● If the compilation fails, the user could invoke an editor to correct the Program;
● If the compilation succeeds, the user could invoke a loader and execute
the program.
● a process or scripting language which generally interpret and have the property that
they view programs and files as the primitive data to manipulate.
● “faster, better, and cheaper.”
 Impact of Machine Architectures

In developing a
Language
architecture of s/w
influences the
design of language
Impact of Machine Architectures - THE OPERATION OF A COMPUTER
Computer Hardware
● A computer is an integrated set of algorithms and data structures capable of storing
and executing programs.
● A computer may be constructed as an actual physical device using wires, integrated
circuits, circuit boards, and the like, in which case it is termed an actual computer or
hardware computer.
● it may also be constructed via software by programs running on another computer,
in which case it is a software-simulated computer.
● A programming language is implemented by construction of a translator, which
translates programs in the language into machine language programs that can be
directly executed by some computer.
Impact of Machine Architectures - THE OPERATION OF A COMPUTER
Computer Hardware
1. Data. A computer must provide various kinds of elementary data items and data
structures to be manipulated.
2. Primitive operations. A computer must provide a set of primitive operations useful for
manipulating the data.
3. Sequence control. A computer must provide mechanisms for controlling the sequence in
which the primitive operations are to be executed.
4. Data access. A computer must provide mechanisms for controlling the data supplied to each
execution of an operation.
5. Storage management. A computer must provide mechanisms to control the allocation of
storage for programs and data
6. Operating environment. A computer must provide mechanisms for communication with
an external environment containing programs and data to be processed.
Impact of Machine Architectures
Impact of Machine Architectures - THE OPERATION OF A COMPUTER

Firmware of Computers

● Common alternative to the strict hardware realization of a computer is the

firmware computer simulated by a microprogram running on a special micro
programmable hardware computer.
● Microprogram simulation of a computer is sometimes termed emulation.
● We also refer to the resulting computer as a virtual computer because it is simulated
by the microprogram; without this microprogrammed simulation, the machine
would not exist.
Impact of Machine Architectures - THE OPERATION OF A COMPUTER

Translators and Virtual Architectures

● Translator could be designed to translate programs in the high-level language into

equivalent programs in the machine language of the actual computer.
● Instead simulate, through programs running on another host computer, a
computer whose machine language is the high-level language.
● We construct with software running on the host computer (the high-level
language computer) that we might otherwise have constructed in hardware. This
is termed a software simulation (or software interpretation) of the high-level
language computer on the host computer.
 Impact of Machine Architectures - THE OPERATION OF A COMPUTER
Translators
● An assembler is a translator whose object language is also some variety of machine language
for an actual computer but whose source language, an assembly language, represents for the
most part a symbolic representation of the object machine code.
● A compiler is a translator whose source language is a high-level language and whose object
language is close to the machine language of an actual computer,
● A loader or link editor is a translator whose object language is actual machine
code and whose source language is almost identical.
Impact of Machine Architectures - THE OPERATION OF A COMPUTER

Translators

● A preprocessor or a macroprocessor is a translator whose source language

is an extended form of some high-level language such as C++ or Java and
whose object language is the standard form of the same language.
Impact of Machine Architectures - THE OPERATION OF A COMPUTER

Translators
Impact of Machine Architectures - THE OPERATION OF A COMPUTER
Software Simulation
● The simulated computer accepts as input data a program in the high-level
language.
● The main simulator program performs an interpretation algorithm similar to that
of decoding and executing each statement of the input program in the appropriate
sequence and producing the specified output from the program.
● host computer creates a virtual machine simulating
● the high-level language.
● When the host computer is executing the high-level program, it is not possible to tell
whether the program is being executed directly by the hardware or is first
converted to the low-level machine language of the hardware computer.
 Impact of Machine Architectures - THE OPERATION OF A COMPUTER

Translators and Virtual Architectures

● Translation and simulation provide different advantages in a programming language
implementation.
● Some aspects of program structure are best translated into simpler forms before
execution; other aspects are best left in their original form and processed only as needed
during execution.
● The major disadvantage of translation is loss of information about the program.
● In Simulation By leaving statements in their original form until they need to be
executed, no space is needed to store multiple copies of long code sequences;
● the basic code need be stored only once in the simulation routine.
● However, the total cost of decoding must be paid each time the statement is to be
executed.
 Impact of Machine Architectures - THE OPERATION OF A COMPUTER
Translators and Virtual Architectures

● The common division of languages

1. Compiled languages : translated into the machine language of the actual computer
being used before execution begins, eg. C, C++, FORTRAN, Pascal, and Ada are
2. Interpreted languages : In such a language implementation, the translator does not produce
machine code for the computer being used. Instead, the translator produces some
intermediate form of the program that is more easily executable than the original
program form yet that is different from machine code.

● Java and the WWW have changed some of these rules.

Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES

1. Through a hardware realization, representing the data structures and algorithms

directly with physical devices.
2. Through a firmware realization, representing the data structures and algorithms by
microprogramming a suitable hardware computer
3. Through a virtual machine, representing the data structures and algorithm by programs
and data structures in some other programming language.
4. Through some combination of these techniques, representing various parts of the
computer directly in hardware, in microprograms, or by software simulation as
appropriate.
Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Virtual Computers and Language Implementations

● The language is implemented on a different computer, the implementor tends to see a

slightly (or very) different virtual computer in the language definition.
● two different implementations of the same language may utilize a different set of data
structures and operations in the implementation,
● three factors lead to differences among implementations of
1. Differences in each implementor’s conception of the virtual computer
2. Differences in the facilities provided by the host computer on which the language is to
be implemented.
3. Differences in the choices made by each implementor as to how to simulate the virtual
computer elements
Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Hierarchies of Virtual Machines
Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Bindings: Names and Attributes

● Names are a fundamental abstraction in languages to denote entities

○ Meanings associated with these entities is captured via attributes associated with the
names
● Attributes differ depending on the entity:
○ location (for variables)
○ value (for constants)
○ formal parameter types (functions)
● Binding: Establishing an association between name and an attribute.
Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Bindings: Names

● Names or Identifiers denote various language entities:

○ Constants
○ Variables
○ Procedures and
○ Functions Types, . . .
● Entities have attributes
 Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Bindings: Attributes

● Attributes are associated with names (to be more precise, with the entities they denote).
● Attributes describe the meaning or semantics of names (and entities).

● An attribute may be
○ static: can be determined at translation (compilation) time, or
○ dynamic: can be determined only at execution time.
Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Binding and Binding Time -Importance of Binding Times
 Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Binding Time -Importance of Binding Times

● Language design time: built-in features such as keywords

● Language implementation time: implementation dependent semantics such as bit-width of an integer
● Program writing time: names chosen by programmer
● Compile time: bindings of high-level constructs to machine code
● Link time: final bindings of names to addresses
● Load time: Physical addresses (can change during run time)
● Run time: bindings of variables to values, includes many bindings which change during execution
Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Binding and Binding Time -Classes of Binding Times

1. Execution time (run time)

a. On entry to a subprogram or block.
b. At arbitrary points during execution.
2. At arbitrary points during execution.
a. Bindings chosen by the programmer.
b. Bindings chosen by the translator.
3. Language implementation time.
4. Language definition time.
Impact of Machine Architectures - VIRTUAL COMPUTERS AND BINDING TIMES
Binding and Binding Time -Classes of Binding Times

● consider the simple assignment statement X=X+10

● Points to Think:
○ Set of types for Variable X.
○ Type of variable X.
○ Set of possible values for variable X.
○ Value of Variable X.
○ Representation of the constant 10.
○ Properties of the operator +.
 Programming Languages

1. Machine languages.

2. Assembly languages.

3. High-level languages.
 Programming Languages
Machine languages and assembly languages are also called low-level languages
● A Machine language program consists of a sequence of zeros and ones.
● Each kind of CPU has its own machine language.
● Advantages
○ Fast and efficient
○ Machine oriented
○ No translation required
● Disadvantages
○ Not portable
○ Not programmer friendly
 Assembly language programs
Use ØAssembly
● Each statement inlanguage programs
assembly language haveto one
corresponds thestatement
same inadvantages and
machine language.
● Assembly language
disadvantages programs
as machine have the programs.
language same advantages and disadvantages as machine
language programs.
Compare the following machine language and assembly language programs:
● Compare the following machine language and assembly language programs:
 High-Level Programming Languages
use●mnemonics to represent
A high-level language machine
(HLL) has instructions
two primary components
○ a set of built-in language primitives and grammatical rules
ØEach statement in assembly language corresponds to one statement in
○ a translator
machine language.
● A HLL language program consists of English-like statements that are governed by a strict
syntax.
ØAssembly language programs have the same advantages and
● Advantages
disadvantages
○
as machine language programs.
Portable or machine independent
○ Programmer-friendly
Compare the following machine language and assembly language programs:
● Disadvantages
○ Not as efficient as low-level languages
○ Need to be translated
○ Examples : C, C++, Java, FORTRAN, Visual Basic, and Delphi.
 Programming Paradigms
● mnemonics
use Why are thereto represent
hundreds machine instructions
of programming languages in use today?
○ Some programming languages are specifically designed for use in certain
ØEach statement in assembly language corresponds to one statement in
applications.
machine language.
○ Different programming languages follow different approaches to solving
ØAssembly programming
language problems
programs have the same advantages and
disadvantages as machine
● A programming paradigmlanguage programs.
is an approach to solving programming problems.
● A programming
Compare paradigm
the following may consist
machine of many
language andprogramming languages.programs:
assembly language
● Common programming paradigms:
○ Imperative or Procedural Programming
○ Object-Oriented Programming
○ Functional Programming
○ Logic Programming
 Programming Paradigms
use mnemonics to represent machine instructions
ØEach statement in assembly language corresponds to one statement in
machine language.
ØAssembly language programs have the same advantages and
disadvantages as machine language programs.
Compare the following machine language and assembly language programs:
 Programming Paradigms- IMPERATIVE and DECLARATIVE
use mnemonics to represent machine instructions
● Imperative
ØEach programming:
statement telling the
in assembly "machine” corresponds to one statement in
language
(computer) how to do something, and as a result
machine language.
what you want to happen will happen.
ØAssembly language programs have the same advantages and
disadvantages as machine language programs.
● Declarative programming: telling the "machine”
Compare thewhat
(computer) following machine
you would like to language
happen, andand assembly language programs:
let the computer figure out how to do it.
 Programming Paradigms- IMPERATIVE and DECLARATIVE
ØEach statement in assembly language corresponds to one statement in
Problem Statement :- Double all the numbers in an array.
machine language.
ØAssembly language programs have the same advantages
Imperative style of programming:
and
Declarative style of programming:
disadvantages as machine languagevarprograms.
var numbers = [1,2,3,4,5] numbers = [1,2,3,4,5]
var doubled = []
Compare the following machine language and assembly language programs:
var doubled = numbers.map(function(n)
for(var i = 0; i < numbers.length; i++) { {
var newNumber = numbers[i] * 2 return n * 2
doubled.push(newNumber) })
}
console.write(doubled) //=> [2,4,6,8,10] console.log(doubled) //=> [2,4,6,8,10]
 Programming Paradigms- PROCEDURAL/STRUCTURED
use
● mnemonics to represent
Procedural programming machine
is a computer instructions
programming language that organises our code into small
programs" that use and change our datas.
ØEach statement in assembly language corresponds to one statement in
● Structured programming is a programming paradigm recommending hierarchical division into
machine language.
blocks of code with one entry point and one or more exit points.
ØAssembly language weprograms
● In structured programming have : the same
use three main structures advantages and
○ sequences (instruction _1; instruction _2;…; instruction _n
disadvantages as machine language programs.
○ choices (if, if...else, switch, case)
Compare the following
○ iterations machine
(while, repeat, for). language and assembly language programs:
● Key words: variables, types, procedures and abstract datas. Using: network systems, operating
systems, etc.
● Procedural/structured languages:
Fortran , Cobol , Pascal, c, ,c++ etc,
 Programming Paradigms- PROCEDURAL/STRUCTURED
use mnemonics to represent machine instructions
ØEach statement in assembly language corresponds to one statement in
machine language.
ØAssembly language programs have the same advantages and
disadvantages as machine language programs.
Compare the following machine language and assembly language programs:
Programming Paradigms-Object-oriented programming
● Object-oriented programming is a programming paradigm in which programs are defined using
objects - the state of the connecting elements (or fields) and behavior (or method).
use mnemonics to represent machine instructions
● Object-oriented computer program is expressed as a set of such objects, which communicate with
ØEacheachstatement
other in orderin assembly
to perform tasks. language corresponds to one statement in
machine language.
● Key words: classes and objects, inheritance, encapsulation, polymorphism.
● Using: www and stand-alone applications.
ØAssembly language programs have the same advantages and disadvantages
● Object-oriented languages
as machine
○ Simula,language programs.
○ Smalltalk,
Compare the following machine language and assembly language programs:
○ C++,
○ C#,
○ Java, others.
 Programming Paradigms- Object Oriented
use mnemonics to represent machine instructions
ØEach statement in assembly language corresponds to one statement in
machine language.
ØAssembly language programs have the same advantages and
disadvantages as machine language programs.
Compare the following machine language and assembly language programs:
 Programming Paradigms-Functional programming
● Functional programming is a programming paradigm in which the functions are the core values ​
and the emphasis is on valuation (often recursive) function, and not to execute commands.
● Theoretical basis for functional programming was developed in the 19330s of the Twentieth century
by Alonzo Church's
use mnemonics lambda calculus,
to represent called instructions
machine lambda calculus with types.
● Key words: functions, lambda calculus, parametric polymorphism.
ØEach statement
● Using: theoretical, inin assembly language
telecommunications, in financial corresponds
calculations. to one statement in
machine language.
● Functional languages:
○ Lisp,
ØAssembly language programs have the same advantages and
○ ML,
disadvantages
○ Haskell, as machine language programs.
○ H#,
Compare the following machine language and assembly language programs:
○ Erlang
○ others.
Programming Paradigms- Functional Programming
use mnemonics to represent machine instructions
ØEach statement in assembly language corresponds to one statement in
machine language.
ØAssembly language programs have the same advantages and
disadvantages as machine language programs.
Compare the following machine language and assembly language programs:
Programming Paradigms- Functional Programming
use mnemonics to represent machine instructions
 Programming Paradigms-Logical programming
● The paradigm of logic programming is a programming method in which the
program is given as a set of relations, and the relationship between these
dependencies.
● mnemonics
use Key words: facts, reports, queries.
to represent machine instructions
● Using:
ØEach theoretical,
statement artificial intelligence.
in assembly language corresponds to one statement in
● Logical
machine languages:
language.
○ Gödel,
ØAssembly language programs have the same advantages and
○ Fril,
disadvantages as machine language programs.
○ Prolog, others.
Programming Paradigms- Logical programming

use mnemonics to represent machine instructions

ØEach statement in assembly language corresponds to one statement in
machine language.
ØAssembly language programs have the same advantages and
disadvantages as machine :
 Programming Paradigms- Logical programming

use mnemonics to represent machine instructions

ØEach statement in assembly language corresponds to one statement in
machine language.
ØAssembly language programs have the same advantages and
disadvantages as machine :
Procedure Object Oriented Function Oriented Logic Oriented

C C++ ML PROLOG

COBOL Java LISP CURRY

FORTRAN Ruby DART FRIL

PASCAL Python SCHEME OZ

Java Script Ada LOGO ALMA-0

Smalltalk
SQL

PhP
THANK YOU