Types of programming language in computer..

  Mainy in computer 48 types of language are occur i.e...
                                          

                      First programming languages


In the 1940s, the first recognizably modern electrically powered computers were created. The limited speed and memory capacity forced programmers to write hand tunedassembly language programs. It was eventually realized that programming in assembly language required a great deal of intellectual effort and was error-prone.
The first programming languages designed to communicate instructions to a computer were written in the 1950s. An early high-level programming language to be designed for a computer was Plankalkül, developed for the German Z3 by Konrad Zuse between 1943 and 1945. However, it was not implemented until 1998 and 2000.[2]
John Mauchly's Short Code, proposed in 1949, was one of the first high-level languages ever developed for an electronic computer.[3] Unlike machine code, Short Code statements represented mathematical expressions in understandable form. However, the program had to be translated into machine code every time it ran, making the process much slower than running the equivalent machine code.

The Manchester Mark 1 ran programs written inAutocode from 1952.
At the University of Manchester, Alick Glennie developed Autocode in the early 1950s. A programming language, it used acompiler to automatically convert the language into machine code. The first code and compiler was developed in 1952 for theMark 1 computer at the University of Manchester and is considered to be the first compiled high-level programming language.[4][5]
The second autocode was developed for the Mark 1 by R. A. Brooker in 1954 and was called the "Mark 1 Autocode". Brooker also developed an autocode for the Ferranti Mercury in the 1950s in conjunction with the University of Manchester. The version for the EDSAC 2 was devised by D. F. Hartley of University of Cambridge Mathematical Laboratory in 1961. Known as EDSAC 2 Autocode, it was a straight development from Mercury Autocode adapted for local circumstances, and was noted for its object code optimisation and source-language diagnostics which were advanced for the time. A contemporary but separate thread of development, Atlas Autocode was developed for the University of Manchester Atlas 1 machine.
Another early programming language was devised by Grace Hopper in the US, called FLOW-MATIC. It was developed for theUNIVAC I at Remington Rand during the period from 1955 until 1959. Hopper found that business data processing customers were uncomfortable with mathematical notation, and in early 1955, she and her team wrote a specification for an Englishprogramming language and implemented a prototype.[6] The FLOW-MATIC compiler became publicly available in early 1958 and was substantially complete in 1959.[7] Flow-Matic was a major influence in the design of COBOL, since only it and its direct descendent AIMACO were in actual use at the time.[8] The language Fortran was developed at IBM in the mid 1950s, and became the first widely used high-level general purpose programming language.
Other languages still in use today, include LISP (1958), invented by John McCarthy and COBOL (1959), created by the Short Range Committee, heavily influenced by Grace Hopper. Another milestone in the late 1950s was the publication, by a committee of American and European computer scientists, of "a new language for algorithms"; the ALGOL 60 Report (the "ALGOrithmic Language"). This report consolidated many ideas circulating at the time and featured three key language innovations:
  • nested block structure: code sequences and associated declarations could be grouped into blocks without having to be turned into separate, explicitly named procedures;
  • lexical scoping: a block could have its own private variables, procedures and functions, invisible to code outside that block, that is, information hiding.
Another innovation, related to this, was in how the language was described:
  • a mathematically exact notation, Backus-Naur Form (BNF), was used to describe the language's syntax. Nearly all subsequent programming languages have used a variant of BNF to describe the context-free portion of their syntax.
Algol 60 was particularly influential in the design of later languages, some of which soon became more popular. The Burroughs large systems were designed to be programmed in an extended subset of Algol.
Algol's key ideas were continued, producing ALGOL 68:
  • syntax and semantics became even more orthogonal, with anonymous routines, a recursive typing system with higher-order functions, etc.;
  • not only the context-free part, but the full language syntax and semantics were defined formally, in terms of Van Wijngaarden grammar, a formalism designed specifically for this purpose.
Algol 68's many little-used language features (for example, concurrent and parallel blocks) and its complex system of syntactic shortcuts and automatic type coercions made it unpopular with implementers and gained it a reputation of being difficult. Niklaus Wirth actually walked out of the design committee to create the simpler Pascal language.
Some important languages that were developed in this period include:


                                                                  BUT

We do not need to know about all language..

Following these languages that are need to learn -:

  1. C (one of the most widely used procedural programming languages)
  2. C++ (One of the most widely used Object Oriented Languages specially used in large scale, highly complex, high performance software systems)
  3. Java (usually compiled into JVM bytecode although true native-code compiled versions exist)
  4. PHP (intended for Web servers)
  5. .NET 


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what is computer language ???

What makes a computer language? Why do computers have them? Why are there so many different computer languages?

                            HISTORY OF PROGRAMMING


 Computers are electronic, and they are digital. To a computer everything is in terms of no voltage potential along a wire, or some voltage available. No voltage means a zero to the computer, and some voltage means a one. Computers can't actually count higher than that without combining multiple ones and zeros.
In the early days, switches were used to load ones or zeros into computer memory.
The front panel switches were used to load in the program. The lights showed the output. There was no monitor.

ALTAIR 8800












Each set of on/off switches represented a number. Each number would represent data or an instruction for the computer to perform. This system of only using ones and zeros to represent numbers is called the binary number system. This type of computer language is called a 1GL, or first generation programming language.
Binary numbers are usually represented in groups of four. For example:
1010 0010 0011
Both data and computer instructions are stored in binary. Machine language are the binary numbers representing instructions that the computer interprets. Not all binary data is machine language however. Data such as documents, databases, financial figures are also stored in binary on the computer. This data is, of course, not intended to be run by the computer.
An improvement over entering programs via switches was the use of hexadecimal codes. The decimal numbers used by most people use the digits 0-9. Hexadecimal uses the numbers 0-9 and A-F to represent a set of four switches, or the numbers 0-15. See the table below for an idea of how binary, decimal, and hexadecimal relate.
BinaryDecimalHexadecimal
000
111
1022
1133
10044
10155
11066
11177
100088
100199
101010A
101111B
110012C
110113D
111014E
111115F
1 00001610
1 00011711

In order to make entering programs easier, later computers allowed users to enter programs using assembly language. Each command used a mnemonic, and a program called a compiler would change the mnemonics into the numbers that represented the commands. This type of language is called a 2GL language, or second generation language.


While this was an improvement, it still wasn't very easy to program. The next generation of languages allowed for higher-level abstractions. The first of the third generation languages (COBOL, FORTRANand LISP) were a lot easier to understand and program.


The second and third generation languages used a program called a compiler. A compiler takes the program typed in by the user (called source code) and turns it into machine code. The programmer then runs the machine code. The original source code is not run.


If there are several pieces of source code in a program, they can be linked together into one program with the use of a program called a linker. The linker is run on the machine code generated by the compiler to generate a final program. This final program is what the user runs, and the original source code is not needed.




A disadvantage of compiling to machine language is that the program only works for that particular type of machine. Programs compiled for Windows computers do not work on Apple Macintosh computers, or Linux computers.


Because the whole compile and link steps could be complex for new programmers, some languages instead ran using interpreters. These programs look at the source code and interpret it to machine language instructions on the fly. It also allows the same programs to run on Windows, Mac, and Unix computers, provided there is an interpreter available for each platform.


The drawback of using interpreters is that it is slower to operate through an interpreter than in the machine's native language.
fig.interpreter
Python is an example of an interpreted language. It is easier to develop in Python than C, but Python runs slower and must have a Python interpreter to work.
Languages such as Java use a system where programs are compiled to machine code that runs on a Java Virtual Machine (JVM), rather than the actual machine. Another popular language that does this is C#, a Common Language Infrastructure (CLI) language that runs on the Virtual Execution System (VES) virtual machine. A full discussion of these is beyond the scope of this book, but feel free to read up on them.
There are many different computer languages today. Because computers perform so many types of tasks, different languages have been developed that specialize in these tasks. Languages such as C are good for operating systems and small embedded computers. Other languages like PHP specialize in creating web pages. Python is a general purpose language that specializes in being easy-to-use.
The company Tiobe keeps track of the popularity of various programming language in their index that is updated each month. It is a good idea to look here, and at job placement boards like DICE to keep up to date with what languages employers are looking for.
Thankfully almost all languages share the same common elements, and once one language has been learned, the same theories will apply to the other languages.

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