Programming Language

1.what is a programming language? who  introduced it?

A vocabulary and set of grammatical rules for instructing a computer to perform specific tasks.

Each language has its unique set of keywords and a special syntax for organizing programming instructions.

Each CPU has its own unique machine language.

Lying between machine languages and high-level languages are languages called assembly languages. Assembly languages are similar to machine languages, but they are much easier to program in because they allow aprogrammer to substitute namesfor numbers. Machine languages consist of numbers only.

Lying above high-level languages are languages called fourth-generation languages (usually abbreviated 4GL). 4GLs are far removed from machine languages and represent the class of computer languages closest to human languages.

Regardless of what language you use , you eventually need to convert our program into machine languages so that the computer can understand it. there are two ways to do this:

1.compile the program

2.interpret the program

The choice of which language to use depends on the type of computer the program is to run on, what sort of program it is, and the expertise of the programmer.

Every language has its strengths and weaknesses.

The first programming langues  designed to communicate instructions to a computer were written in 1950s.

Ada Lovelace based on the work ofLuigi Menabrea, created the firstalgorithm designed for processing by a computer and is usually recognized as history's first computer programmer

 work on Charles Babbage's early mechanical general-purpose computer, the Analytical Engine

2.what is the use of a programming language?

used  to give instructions to the computer

3.what are the types of programming langues?

1.Machine Language: low-level programming language.

2.Assembly Language : representation of machine language 

3.high Level Language : most programmers use .

     1. functional languages

ex:Scala, F#, Clojure and Lisp.

     2. procedural languages 

Ex : COBOL, FORTRAN and C

     3. object oriented languages

ex:Java, C# and C++ 

     4. logic programming languages.

eg: Logic language

• Assembly
• Procedural
• Basic
• C
• Object-Oriented
• C#
• Java
• Declarative
• Prolog
• SQL
• Functional
• Lisp
• Haskell
• Pattern based: 
• Perl,
•  Regex,
•  Snobol.
• Tree based: 
• XSLT.
• Array based: 
• APL.

The different generations of languages

There are currently five generations of computer programming languages. In each generation, the languages syntax has become easier to understand and more human-readable.

• First generation languages (abbreviated as 1GL) 
  Represent the very early, primitive computer languages that consisted entirely of 1's and 0's - the actual language that the computer understands (machine language).
• Second generation languages (2GL) 
  Represent a step up from from the first generation languages. Allow for the use of symbolic names instead of just numbers. Second generation languages are known as assembly languages. Code written in an assembly language is converted into machine language (1GL).
• Third generation languages (3GL) 
  With the languages introduced by the third generation of computer programming, words and commands (instead of just symbols and numbers) were being used. These languages therefore, had syntax that was much easier to understand. Third generation languages are known as "high level languages" and include C, C++, Java, and Javascript, among others.
• Fourth generation languages (4GL) 
  The syntax used in 4GL is very close to human language, an improvement from the previous generation of languages. 4GL languages are typically used to access databases and include SQL and ColdFusion, among others.

Fifth generation languages (5GL) 
Fifth generation languages are currently being used for neural networks. A neural network is a form of artificial intelligence that attempts to imitate how the human mind works.
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OBJECT ORIENTED PROGRAMMING LANGUAGE

what is object oriented programming language?
Object means a real world entity such as pen, chair, table etc. Object-oriented programming is a methodology or paradigm to design a program using classes or objects. it simplifies the software development and maintenance with some concepts:
  1.Object
  2. Class
  3. Inheritance
  4. Polymorphism
  5. Abstraction
  6. Encapsulation

1. Object : Any entity that has state and behaviour is known as object. ex: chair,pen, table etc. it can be physical or logical.
2. Class : Collection of objects is called class. it is a logical entity.
3. Inheritance : when one  object acquires  all the properties and behaviours of parent object i.e. known as inheritance. It provides code re usability .It is used to achieve runtime polymorphism.
4. Polymorphism: when one task is performed by different ways. i.e. known as polymorphism. For Example : to draw something e.g : share or rectangle etc.
   In java we use method overloading and overriding for achieving polymorphism.
   ex: speak something
   
5. Abstraction: Hiding internal details and showing functionality is known as abstraction.
   Ex: phone call we don't know the internal processing.
   in java we use Abstract class and interface to achieve abstraction.
6. Encapsulation: Binding (or wrapping ) code and data together into a single unit is known as encapsulation.
   ex: capsule ,it is wrapped with different medicines.A java class is the example for encapsulation , java bean is the fully encapsulated class because all the data members are private here. 

OOPS is a programming language model organized around "objects" rather than "actions" data rather than logic.
Generally program has been viewed as logical procedure that takes input data, processes it, an produces output data.
ex : human beings(described by name, address, and so forth), to buildings and floors(whose properties can be described and managed) down to the little widgets on a computer desktop(buttons and scroll bars)
First step in OOP is to identify the objects the programmer wants to manipulate and how they are related to each other, an exercise often knowns as data modelling.
Each distinct logic sequence is known as a method. Objects communicate with well-defined interfaces called messages.
Object oriented programming concepts:

Simula was the first object-oriented programming language.
JAVA, Python , C++, Visual Basic,  .NET, and Ruby are the most popular OOPS languages today.
The Java programming language is designed especially for use in distributed applications on corporate networks and the internet.
Ruby is used in many web applications .
Curl, Smalltalk, Delphi and Effel are also examples of object-oriented programming languages.
smalltalk is considered as the first truly object-oriented programming language.the programming paradigm where everything is considered as object is called truly object oriented.
OOPSLA is the annual conference for Object-Oriented Programming Systems, Languages and Applications.