Computer Programming Languages

PROGRAM:
Program is a collection of well defined instructions and the art of writing instructions for a computer to solve a particular task is known as programming.

SOFTWARE:
Software is a collection of programs and it cannot be touched. Software developed with the help of programming languages. Programming languages is the medium of communication between the man and the machine. There are different programming languages.

COMPUTER LANGUAGES:

These are classified into low level and high level programming languages. Low level languages are those which are easily understood by machines. High level languages are those which are nearer to natural languages that is English.
 

                                  
                                     CATEGORIES OF PROGRAMMING LANGUAGES

PROGRAMMING LANGUAGES: 2 TYPES   HIGH LEVEL LANGUAGES LOW LEVEL LANGUAGES     LOW LEVEL LANGUAGES: 2 TYPES MACHINE LANGUAGES ASSEMBLEY LANGUAGES    HIGH LEVEL LANGUAGES: 2 TYPES        GENERAL PURPOSE HLL SPECIFIC PURPOSE HLL

LOW LEVEL LANGUAGES: 

These languages are easily understood by computer. Machine and Assembly languages are the example of low level languages. They are machine dependent languages that is program written in these languages are not transferable from one computer to another.

CLASSIFICATION OF LOW LEVEL LANGUAGES:

• Machine Languages
• Assembley Languages

MACHINE LANGUAGES:

It is considerd as First Generation Languages because programming was started with this language. The comuter only understand two words that is zero and one and these digits are known as binary digits. A binary number system consist of binary digits. 0 indicates low voltage level and 1 indicates high voltage level.

An instruction consist of 0's and 1's. Instruction consist of 2 fieds                                   

OPCODE        4 BIT

ADDRESSS          8 BIT

•  OPCODE indicates what operation is to be done that is addition,substraction etc

• ADDRESS indicates the memory location where in the data is referenced.

NOTE:The length of each instruction is 12bits that is 4 bits for OPCODE and 8 bits for ADDRESS.

Example:

0001 00110010

The above instruction load data into accumulator.

ASSEMBLY LANGUAGE:

To overcome the drawbacks of machine language , computer engineers developed a new programming language which uses symbolic instructions. Symbolic instruction oriented programming language is known as Assembly language.

This is called Second Generation Programming language because this language is used after machine language.

Since the instructions of assembly languages are English like and computer does not understand these instructions. So we translate these language instructions into machine instruction (which is understoodable to computer) with the help of ASSEMBLER( TASM , MASM).

NOTE:Instructions of Assembly language differ from one computer to another means for different-2 computers instructions are also different.

EXAMPLE:

ADD X,Y

Above instruction ADD adds the contents of Y to X.

HIGH LEVEL LANGUAGES:

The element of these languages are alphabets,digits, punctuations and other special symbols. The instructions are composed of these elements. Hence each and every instruction is easy to understand and read. Instructions are machine independent that means program written in one computer can be executed on other computer with very little or no modification. This feature provide flexibility to programmer.

EXAMPLE:

SUM =A+B : add the contents of both A and B and store in SUM.

The programmer understands this program easily but the computer does not. Hence, it is require to translate this program into computer readable form that is machine language. By the use of translator we translate high level language program into machine language.

Compiler and Interpreter are two translator programs that are used to translate high level language programs into machine language. High level language program is called Source Program. After translation the obtained program is called Object Program.

CLASSIFICATION OF HIGH LEVEL LANGUAGES:

High level languages are of two types:

• General Purpose HLL
• Specific Purpose HLL