Introduction to programming languages
A set of instructions used by a computer to solve a problem is called a program. The language used to write programs is called programming language. Initially machine language was used as a programming language but later assembly language and high level languages came into vogue. C is such a procedural programming language.
Concept of Program:
A set of instructions used by a computer to solve any mathematical or logical problem is called a program. The process of writing programs is called programming. Any complex problem can be solved easily with proper programming. The number of instructions used in program writing depends on the type of problem.
Programming Language :
Computer is a powerful device. It is suitable for complex tasks. It is not possible to do any work with it unless it is properly told what to do. So what needs to be done must be explained to the computer in such a way that it can understand it and carry it out to the letter. Although billions of people in the world have thousands of different languages, computers do not understand even one of them. That is, the computer understands its own mechanical language which is made of 0 and 1. Understanding machine language is difficult for humans. A program is an arrangement of words, letters, symbols etc. used according to certain rules to give instructions to the computer in its own understandable language. The words, letters, symbols used and their formatting rules together are called the programming language. That is, the language used to give instructions to the computer is called program language. Programming on computers was difficult in the early stages but nowadays it can be done easily without any knowledge of the machines. And this is possible only because of the research and development of programming languages. Programming in high-level languages is a revolutionary change in the world of programming.
Language level:
-- Low level language
--- Machine language
--- Assembly language
-- High level language
The languages used to write programs used by computers to solve problems are called programming languages. Different programming languages are used to solve different types of problems. Each programming language has different rules for using it. Just as human languages in different countries of the world have their own rules, so programming languages have different syntax. Currently the most widely used languages in computers are C, C++, Visual Basic, Java, Oracle, Python, HTML etc.
Low level language:
A low-level language is a language in which the programs written are machine-dependent. Programs written in this level language. Does not run on any computer. Programs written in low-level languages are relatively complex. Machine language and assembly language are examples of low-level languages.
Machine Language :
The basic language of computer programming is machine language. Whatever language the program is written in eventually translates into machine language. Computer takes the least time to read this language. But all the instructions and data of machine language are written in binary system. So program coding is not understandable. This makes programming in machine language very complicated. Moreover, the use of machine language of each computer is different, so the program made for one computer cannot be used on another computer. A machine language instruction consists of two parts.
(1) Opcode (2) Operand
Assembly Language:
To avoid the complexity of creating programs in machine language, this language began to be used in the 1950s and became widely used in the second generation of computers. It is known as sign language. Instructions and information in this language are decimal or hexadecimal. Assembly language was developed to speed up programming by making the difficult task of programming in machine language relatively easy and also by saving time and facilitating the work of correcting and modifying the written program. In assembly language, the binary signals originally from machine language are somewhat abbreviated. This short signal is called Mnemonic Code. eg ADD for addition and SUB for subtraction. Each instruction in this language has four parts. Namely (1) label (2) op-code (3) operand and (4) comment
Mid Level Language:
Some programming languages have high-level features but are closer to low-level languages such as C. C++ C has some operators ++, which in low-level languages indicate increment and decrement for which CPU. In this language, the location of computer memory and other hardware can be controlled in the same way as low-level languages. C programming language is mostly used for system programming. Hardware configuration, interrupt (interrupt) management, etc. can be done easily through the use of pointers. Also, C is called a middle-level language because it is not as difficult as COBOL or ALGOL, and not as easy as machine language or assembly language. Moreover, the C compiler can compile programs written in assembly language and programs written in high-level languages. So system software and application software can be created through it.
High Level Language:
A language in which programs are written at a level that is not machine-dependent is called a high-level language. In the mid-1950s, high-level languages became popular in programming. Most high-level languages follow the basic guidelines of the American National Standards Institute. Programming language is not as complex as machine language and not as machine dependent as assembly language. High-level programming languages are generally similar to the English language. Most of the words in this language are common English words. So people who know basic English can write programs in high level languages. But since the computer does not understand anything except binary language i.e. machine language, so in this case two translator programs called compiler and interpreter are used to make the program written in high level language understandable to the computer. A high-level language is also called a procedural language as it divides a large program into different processes or parts. The program written in mechanical language is called Object Code and the program written in high level language is called Source Code. Examples of high level languages are BASIC, COBAL, ALGOL, PASCAL, FORTRAN, AADA, C etc.
Practical computer programs need to be such that the program can be easily modified, extended, debugged and maintained. High level programming languages are not machine dependent ie programs written in high level languages can be used on different types of computers. Following are some important features of high level languages:
(i) Learning is easy.
(ii) Identification and correction of program errors becomes easier.
(iii) Higher level language can use many words of normal language (eg English).
(iv) Program function statements or statements are equivalent to many machine (or assembly) statements.
(v) Availability of various types of library programs.
(vi) Do not think about the machine while writing the program.
(vii) High-level languages have syntax rules like normal languages.
A brief introduction to some high-level languages is given below:
C : C was born in the 1970s; Dennis Ritchie of Bell Telephone Laboratories (now AT&T Laboratories) developed the 'C' language. Two other languages developed at Bell Laboratories, BCP and B, were used to create this language. Until 1978, the C language was primarily used within Bell Laboratories. In 1978, Brian W. Kernigan and Dennis Ritchie wrote a book on C language, which became widely popular in the field of science and technology. C's popularity as a very powerful and functional language is now widespread.
Java : In 1991, James Gosling (James Gosling) created the modern programming language called Java. Java was originally named (Oak). In 1994, Oak was renamed Java. It is simpler than C++ and is not platform dependent. Internet based applications are useful. Java applications run on different operating systems.
Oracle : Oracle as a database management system program language in 1979. Its first version is released. Oracle is more convenient than other Database Management System (DBMS) in data storage, processing, security etc. Oracle DBMS is equally useful in both single computer and network system environments. Oracle is currently available in both Personal Computer and Server System versions. Personal version is used on single computer and server version in network environment.
Algol : The full name of Algol is Algorithmic Language. This language was invented in 1958 as a universal language to solve various problems in computer science. This language originated in Europe but did not gain popularity outside of Europe.
Fortran: It is the first high-level language. The full name of Fortran is Formula Translator. This language was used in IBM 704 computer in 1956. This language was created to solve various complex numbers. In this language, the computer can be instructed to solve complex mathematical problems in plain and simple English. In the 1960s several improved versions of Fortran came into the market.
Python: Python is a type of high level language. It is relatively easy to write programs with it. Python can be used to speed up processing and successfully integrate different parts of the computer. It runs under Windows, Linux and Mac OS operating systems. Python is a type of open source software. It can be downloaded and used for free from the internet. Through this, web programming, database creation, educational software, gaming software etc. can be created easily.
Fourth Generation Language (4GL):
The problem oriented languages developed for use in computers are called fourth generation languages. These languages are also called very high level languages. All database management software are examples of problem-oriented languages. Structure of reports and screen results, specification of data, records, input data etc., ability to use simple query instructions are features of this language. Writing programs in all these languages is relatively easy. Languages used primarily for commercial applications are often called application generators. Examples of fourth generation languages are Oracle, SQL/DS, Visual Basic, Rapport etc. Programs can be easily written using these languages.
Translational Program :
A program that is used to convert a source program into a destination program is called a translator program. Computers cannot understand programs written in any language other than machine language, but writing programs in machine language is difficult for humans. It is convenient for humans to write programs in assembly language or high level language. But computers cannot understand assembly language or high-level languages. So the program used to convert assembly language or high level language program into machine language is called translator program.
There are three types of translator programs. namely--
1. Assembler
2. Compiler
3. Interpreter
Assembler : The translator program used to convert the program written in assembly language into machine language is called assembler. This conversion involves loading the assembler program into computer memory, which converts each assembly language instruction into machine language. Checking each instruction of coding is correct and notifying if not. The assembler holds every instruction it needs in memory. The assembler also instructs the control unit to execute the program to perform the debugging process.
Compiler: The translator program used to translate the source program written in high level language into machine language is called compiler. With the help of auxiliary memory it comes to the main memory and performs the necessary functions. The work of compiler is more complex than the work of assembler. Because, the process of converting a high-level language program to machine language is more complicated than converting an assembly language program to machine language. Compiler translates each piece of programming code into machine language at once. Currently each high-level language has its own compiling system. It is not possible to translate coding from one language to another with a compiler. The compiler also judges the quality of the programming as well as the conversion. The compiler reads all the instructions of a program and converts them into machine language at once.
Interpreter: Interpreter converts programs written in high-level language into machine language. But its specialty is that each statement is converted to machine language separately, i.e., each statement from the high-level language is sequentially executed. The compiler has to decode the entire coding from scratch. The biggest advantage of the interpreter is that it is very easy to debug or make any changes to the program later. Because, in this case, only the changed part has to be converted. Also it uses less memory. The main disadvantage of the interpreter is that it is very slow. In some cases the interpreter takes about 20 times the time of the compiler. Using a compiler, once a program is executed, it remains permanently translated, but with an interpreter, each statement needs to be translated into a new machine language each time it is executed.
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