A language is defined as the way of communication between two persons. Therefore, computer-programming language is defined as a way of communication between user and the computer. The instructions are given to the computer to perform a specific task. These instructions are given to the computer according to the rules of programming language.
Computer programming languages are used to prepare computer programs or software. Early computer programs were prepared directly in machine language i.e. in binary code. It was very difficult to prepare program in machine code. Today, there are several programming languages, each programming language has its own rules for Writing the program. Each language is also used for specific purpose. For example, Fortran is used for scientific purposes, Cobol for business solutions, Ada for defense applications etc.
Programming languages are divided into two types:
1. Low-level languages
2. High-level languages
Low-Level Languages
The programming languages that are very close to machine code (0s and 1s) are called low-level programming languages. The program instructions written in these languages are in binary form. The examples of low-level programming languages are machine language & assembly language.
1. Machine Language
The instructions in binary form, which can be directly understood by the computer (CPU) without translating them, is called a machine language or machine code. Machine language is also known as first generation of programming language. Machine language is the fundamental language of the computer and the program instructions in this language L1V n the binary form (l’s and 0’s). This language is different for different computers. It is not easy to learn.
2. Assembly Language
It is another low-level programming language because the program instructions written in this language are close to machine language. Assembly language is also known as second generation of programming language. With assembly language, a programmer writes instructions using symbolic instruction code instead of binary codes. Symbolic codes are meaningful abbreviations such as SUB is used for subtraction operation, MUL for multiply operation and so on. Therefore, this language is also called the low-level symbolic language. The set of program instructions written in assembly language are called mnemonic code. Assembly language provides facilities for controlling the hardware.
High-Level Languages
The programming languages that are close to human languages (e.g. like English language) are called the high-level languages. The examples of high-level languages are FORTRAN, COBOL, BASIC, PASCAL, C++ etc.
The high-level languages are similar to English language. The program instructions are written using English words, e.g. print, input etc. But each high-level language has its own rules or grammar for writing program instructions. These rules are called syntax of the language. The program written in high-level language must be translated to machine code before to run it. Each high-level language has its own translator program.
The high-level programming languages are further divided into:
1. Non - Procedural languages
Non -procedural programming languages are also, known a fourth generation languages. In non-procedural programming languages, the order of program instructions is not important. The importance is given only to “what is to be done”. With a non-procedural language, the user (programmer) writes English like instructions to retrieve data from databases. These languages are easier to use than procedural languages. Thus the non-technical users can access data from databases using non-procedural languages. These languages provide the user-friendly program development tools to write instructions. The programmers have to not spend much time for coding the program. The most important non-procedural languages and tools are discussed below.
1. SQL
SQL stands for Structured Query Language. SQL is very popular database access language and is specially used to access and to manipulate the data of databases. The word Query represents that this language is used to make Queries (or inquiries) to perform various operations on data of database. However, SQL can also be used to create tables, add data, delete data, update data of database tables etc.
2. RPG
RPG stands for Report Program Generator. This language was introduced by IBM to generate business reports. Typically, RPG is used for application development on IBM midrange computers, such as AS/400.
2. Procedural Languages
Procedural languages are also known as third Generation languages (3GLs). In a procedural language, a program is designed using procedures. A procedure is a sequence of instructions having a unique name. The instructions of the procedure are executed with the reference of its name.
In procedural programming languages, the program instructions are written in a sequence or in a specific order in which they must be executed to solve a specific problem. It means that the order of program instructions is very important. Some popular procedural languages are described below:
1. FORTRAN
FORTRAN stands for FORmula TRANslation. It was developed in 1957 for IBM computers. It was the first earliest high-level programming language used to introduce the concept of modular programming. It has been revised many times. Its commonly used version is FORTRAN 77.
2. COBOL
COBOL stands for Common Business Oriented Language. It was developed in 1959. This high-level language was specially developed for business and commercial applications; it was suitable for handling large amount of data such as:
- To prepare payroll.
- To process credit and debit account.
- To control inventory system and many other business applications.
3. PASCAL
This programming language is named in the honour of Pascal, a mathematician and scientist who invented the first mechanical calculator. structured programming language and is popular in computer science developed in 1971. It is suitable for scientific field.
4. ADA
It is developed in 1980 and is named in the honour of Lady Augusta ADA. She is the first computer programmer. The high-level structured language Pascal was used as a model for the development of ADA language.
This language is mainly used for defense purposes such as for controlling military weapons like missiles etc.
5. C-Language
Dennis Ritchi and Brian Karnighan developed it in 1972 at Bell Laboratories. It is a high-level language but it can also support assembly language codes (low-level codes). It is because; C-language is also referred to as middle-level language. The program written in C can be compiled and run on any type of computer. In other words, programs written in C-language are portable.
C-language is a structured programming language. The main feature of C- language is that, it uses a large number of built-in functions used to perform various tasks. The user can also create its own functions.
C-language was designed for writing system software. Today, many software are written in C. They include operating systems and application programs. UNIX operating system is also developed in C. Like assembly and machine language, C- language also provides facilities for controlling the hardware. It is also used to solve business and scientific problems. It is a general- purpose language.
3. Object-Oriented Programming Languages
The object oriented programming concept was introduced in the late 1960s but now it has become the most popular approach to develop software. In object oriented programming, the software is developed by using a set of interfacing objects. An object is a component of program that has a set of modules and data structure. The modules are also called methods and are used to access the data from the object. The modem technique to design the program is object-oriented approach. It is a very easy approach, in which program is design by using objects. Once an object for any program is designed, it can be re-used in any other program. Now-a-days, most popular and commonly used object oriented programming (OOP) languages are C++ & JAVA.
1. C++
C++ was developed in early 1980s by Bjarne Stroustrup. It is an object- oriented programming (OOP) language. It is an extension of C programming language. C++ includes all the elements of the C language plus it has additional features for working with objects, classes, events and other object-oriented concepts. Most of the application programs, such as word processing and spreadsheet program are developed in C-H-. It can also be used to develop database systems and web applications.
2. JAVA
Java is another powerful object oriented-programming language. It รง5 developed in 1991 by Sun Microsystems. It is very similar to C++ but it is especially used for web page designing. The Java programming language is a general-purpose language, Like C & C++, any kind of problem can be solved in this language.
The Byte Code Interpreter program is used to run the Java program. This program is also called the Java Virtual Machine. The byte-code interpreter is not dependent on any specific computer. It can be used on any computer.
Java applets are developed in Java language. A java applet is a small Java program that runs inside another program such as web browser. Both -Internet Explorer and Netscape Navigator can run Java applets. The Java applets are embedded into web pages to rotate images, for animations and to access databases on the Internet.
3. Visual Programming Language
The term visual programming refers to creating or developing Windows-based applications or graphical user interface applications. The visual programming languages, sometimes called fifth-generation languages. These are object-oriented programming languages. These languages provide visual or graphical interface facilities to develop GUI applications. The most popular and widely used visual programming language is Visual Basic (VB).
Visual Basic (VB)
Visual Basic is an object-oriented programming language. Visual Basic was developed by Microsoft Corporation of USA in 1991. It is used to create application programs that can only be executed into Windows operating system. The commands of application programs are appeared on the screen in the form of small buttons or images and pull down menus etc. Each of these is referred to as object.
Visual Basic has large number of built-in controls or objects displayed into its toolbox during program designing. Using these objects, the programmer can design the application very easily and rapidly.
Advantages of High-Level Languages
There are several advantages of high-level programming languages. The most important advantages are:
1. Easy to Learn
The high-level languages are very easy to learn than low-level languages. The statements written for the program are similar to English like statements.
2. Easy to Understand
The program written is high-level language by one programmer can easily be understood by another because the program instructions are similar to the English language?
3. Easy to Write Program
In high-level language, a new program can easily be written in a very short time. The larger and complicated software can be developed in few days or months.
4. Easy to Detect & Remove Errors
The errors in a program can be easily detected and removed. Mostly the errors are occurred during the compilation of new program.
5. Built-in Library Functions
Each high-level language provides a large number of built-in functions or procedures that can be used to perform specific tasks during designing of news programs. In this way, a large amount of time of programmer is saved.
6. Machine Independence
Program written in high-level language is machine independent. It means that a program written on one type of computer can be executed on another type of computer.
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