Programming language

Programming Language: An artificial language used to write programs that can be translated into machine language and then executed by a computer. As we know that computer understands only machine language. It does not understand the English language or any other what we normally use. So to perform tasks from computer we use programming language to write programs. These programs tell the computer what to do? Each natural language has a method of using symbols of that language. In English, the method is given by the rules of the grammar. These rules tell us which word to use when and how to use it. Similarly, the rules of a programming language must also be used. These rules are known as “Syntax Rules”. In case of natural language people can use poor and incorrect language, but in case of programming language we can’t use. Each language has strict syntax rules and these rules cannot be ignored. Each program has its own syntax and this is further converted to machine language. Now after the conversion, machine is able to understand the task. This conversion is done by compiler or interpreted. A compiler or interpreter is tool that converts the program into machine language. Each programming has its own compiler or interpreter. Programming language can be classified into three broad categories: 1) Machine Language 2) Assembly Language and 3) High Level Language.

Machine Language: It is the language of the computer machine itself. A machine can understand this language directly without any translator. It is also known as Binary language. It is only two digits language i.e. 0s and 1s. It is first generation of the programming languages. Machine language was used when the computer was of a huge size; approximately it covered one room.

                        Only the developers could work with the computer. Because it was not easy as it is today. Input was firstly converted into the Binary language of zeros and ones. Then fed to computer, computer processed it and output is generated. This output is also in the form of machine language. Again it was converted to human understandable language English. Thus it was a headache giver task.

                        Machine language is the fundamental language of the machines. Each machine we see today works on the machine language. We give input in English and machine works on the machine code.  Some interfaces are there that converts our language into machine language. The circuitry of a machine is wired in such a way that it immediately recognizes the machine language and operates the machine.

                        Machine language is not very easy language to learn. It is difficult to read and understand. The most important advantage of machine language is that programs written in machine language are executed very fast by the computer. This is mainly because machine language is directly understood by the CPU and no translation of the program is required. However writing a program in machine language has several disadvantages; Machine Dependent, Difficult to program and Difficult to modify. Machine dependent means the machine code of one machine will not work for other machine.

                        Machine Language is the toughest language of all the generations. Only developers of this language and experienced scientists can use this language. New learner or normal users can’t even understand it because of its complexity.

Assembly Language: In machine language we write the programs in binary code i.e. 0s and 1s. That is headache giver task. But this headache is reduced by the Assembly Language. In Assembly Language, programs can be easily written in alphanumeric symbols instead of 0s and 1s. For good and effective programming, meaningful and easily remember able symbols are selected. For example: ADD for addition, SUB for subtraction, CMP for comparison etc. Such symbols are known as Mnemonics. A language which uses these mnemonics symbols is known as Assembly Language. A program written in assembly language is known as assembly language program.

The advantage of assembly language is that the execution time of an assembly language program is less. An assembly language program runs faster to produce results.

The most disadvantage of assembly language is that programming in this language is difficult and time consuming. Assembly language is machine dependent. The programmer must have detailed knowledge of the structure of the computer. He must have the knowledge of registry of the computer. The program written in assembly language for one computer cannot be used in any other computer. It means that the assembly language program is not portable. Each processor has its own instruction sets and hence its own assemble language.

High Level Language: A language, in which instructions are written, is called High Level Language. The instructions written in a high level language are called statements. These statements are closer to English and mathematics as compared to mnemonics in assembly languages. Example of high level languages are BASIC, PASCAL, FORTRAN, COBOL, ADA, C, C++, C# and JAVA etc.

High level languages are independent of computer architecture. A programmer does not need knowledge of architecture of the computer. The programming is easier. The same program can run on any other computer which has a compiler of that language. The compiler is machine dependent but not the language. Thus language is machine independent.

High level languages are very similar to English like language. These are easy to learn and use. The programmer needs not to learn anything about the computer. He need not to worry about how to store the code in the computer, where to store them, what to do with them etc. All this was in the previous languages.

Writing programs in high level languages requires less time and effort. Programs written in high level languages are easier to maintain than assembly language or machine language programs. This is because these are easier to understand, easier to correct and modify. Insertion or removal of instructions from a program is also possible.

Disadvantage of high level language is that it takes more time to run and requires more computers’ main memory.

Source and Object Language: The language in which a programmer writes programs is called source language. It may be high level language or an assembly language. The language in which the computer works is called object language or machine language. A program written in a source language is called a source program. When source program is converted into machine code by an assembler or compiler it is known as an object program. In other words, a machine code program ready for execution is called an object program.