Introduction to C Programming Language

C is a structured programming language that was designed originally by Dennis Ritchie, working at At & T Bell Laboratories in New Jersey. it is one of the most widely written computer programming languages in the world. It is easy for debugging, testing, and maintenance and has a remarkable language.

It is one of the most popular computer programming languages today because it’s high-level structured and machine-independent. we can develop programs without worrying about the hardware platform no matter where they will be implemented. 

It is also called a high-level compiler language. and the main aim of C is to provide an easy and natural way to give instructions to a computer. it is also used for general-purpose programming, which means we can write small programs for complex applications.

This programming language has features that allow a program to be organized easily and logically. and it is an essential feature for writing complex and large applications.

It allows meaningful variable names and meaningful function names to be used in programs. that gives us the power to write code more efficiently and with complete freedom of style, also it has a set of constructions and decision-making functions that are used to control the flow of programs. 

C give used to build a compact and neat program and tries to make the best of a computer by linking as closely as possible to the local environment. It has also several pre-defined header files, data types, variable names, functions, and directives to handle the complex part of the program.

Also, it has some powerful operators like increment and decrement that give us the power to reuse the code with the functions and pointers that help us to take the reference of variables.

The development process of C programming started with an older language called BCPL developed by Martin Richards. It is also called a middle-level programming language. and that is not because it is harder to use. rather c is the language that combines the elements of high-level languages with the control and flexibility of assembly language.

C allows the manipulation of bits, bytes, and addresses, as basic functions, and elements that run the computer. another feature is that the code written in C is also very portable. means if we write code for one software then it can also be implemented by other software.

Every high-level programming language supports the concept of data type that defines a set of values. and C supports some good data types like integer, character, and floating-point. apart from that c has also several built-in data types. Unlike other high-level programming languages, c cannot check for no run time error. means it previously didn’t determine whether a given array was overrun by its length or not.

High level	Middle level	Low level
Ada	Java	Assembler
Modula-2	C++
Pascal	C
COBOL	FORTH
FORTRAN	Macro-assembler
BASIC

C has only 37 reserved keywords. in C89 there are 32 keywords defined and in C99 only 5 more keywords are added. but most other high-level languages have a large list of keywords. and by the keywords mean a programming language has some pre-defined words for some specific work. and we can’t use these reserved words for any other work and we can’t overwrite their functionalities.

C is also a Structured programming language. means C follows a Structure to write code. but that rule can’t strictly apply to C. it is just a simple structured programming language. a structured programming language uses a variety of functionalities and supports several loops, jump statements, and functions.

Non-Structured	Structured
FORTRAN	Pascal
BASIC	Ada
COBOL	C++
	C
	Java
	Modula-2

In c a program’s main structure is defined by the functions. functions are the building blocks in which all the activity of a program occurs. like the main() function in C Program. Using the functions we can define the separate task in a program. there are some programming languages like COBOL and BASIC that are not made for programmers.

But C was created and field tested by the programmers and worked for programmers. and in a simple line, we can say “C gives a programmer what the programmer needs”. Initially, c was used for system programming that forms a portion of the computer’s operating system or makes support utilities like compilers, liners, and editors.

Because of its portability and efficiency, many programmers used it in their all tasks and because they liked it! at the time of its creation. but at the time of C++ programming creation, some programmers thought that C would be replaced with C++ but that case doesn’t happen. because not all programs or applications require the object-oriented programming features that are provided by C++. also another main reason is that most of the application was created in C programming at the time of C++. so which also keep back C++ from the place of C.

What is C programming?

C is a programming language developed at AT & T’s Bell Laboratories in the USA in 1972. it was designed and written by a man named Dennis Ritchie. In the late seventies, C began to replace the more familiar languages of that time like PL/I, ALGOL, etc. No one pushed C. It wasn’t made the ‘official’ Bell Labs language thus, without any advertisement C’s reputation spread and its pool of users grew. Ritchie seems to have been rather surprised that so many programmers preferred C to older languages like Fortran or PL/I, or the newer ones like Pascal and APL. But, that’s what happened.

Possibly why C seems so popular because it is reliable, simple, and easy to use. Moreover, in an industry where newer languages, tools, and technologies emerge and vanish day in and day out, a language that has survived for more than 3 decades has to be really good.

An opinion that is often heard today is – “C has been already superseded by languages like C++, C#, and Java, so why bother or learn C today”. I seriously beg to differ with this opinion. There are several reasons for this.

I believe that nobody can learn C++ or Java directly. this is because while learning these languages you have things like classes, objects, inheritance, polymorphism, templates, exception handling, references, etc. to deal with apart from knowing the actual language elements. learning these complicated concepts when you are not even comfortable with the basic language elements is like putting the cart before the horse. Hence one should first learn all the language elements thoroughly using C language before migrating to C++, C#, or Java. Though this two-step learning process may take more time, in the end of it you will definitely find it worth the trouble.

C++, C#, or Java makes use of a principle called Object Oriented Programming (OOP) to organize the program. This organizing principle has lots of advantages to offer. but even while using this organizing principle you would still need a good hold over the language elements of C and the basic programming skills.

Though many C++ and Java-based programming tools and frameworks have evolved over the years the importance of C is still unchallenged because knowingly or unknowingly while using these frameworks and tools you would be still required to use the core C language elements – another good reason why one should learn C before C++, C# or Java.

Major parts of popular operating systems like Windows, UNIX, and Linux are still written in C. This is because even today when it comes to performance (speed of execution) nothing beats C. Moreover, if one is to extend the operating system to work with new devices one needs to write device driver programs. these programs are exclusively written in C.

Mobile devices like cellular phones and palmtops are becoming increasingly popular. also, common consumer devices like microwave ovens, washing machines, and digital cameras are getting smarter by the day. this smartness comes from a microprocessor, an operating system, and a program embedded in these devices. these programs not only have to run fast but also have to work with a limited amount of memory. No wonder that such programs are written in C. With these constraints on time and space, C is the language of choice while building such operating systems and programs.

You must have seen several professional 3D computer games where the user navigates some object, like say a spaceship, and fires bullets at the invaders. the essence of all such games is speed. Needless to say, such games wouldn’t become popular if they take a long time to move the spaceship or to fire a bullet. to match the expectations of the player the game has to react fast to the user inputs. this is where C language scores over other languages. many popular gaming frameworks have been built using the C language.

At times one is required to very closely interact with the hardware devices. since c provides several language elements that make this interaction feasible without compromising the performance it is the preferred choice of the programmer.

I hope that these are very convincing reasons why one should adopt C as the first and very important step in your quest for learning programming languages.

Getting Started with C

Communicating with a computer involves speaking the language the computer understands, which immediately rules out English as the language of communication with the computer. However, there is a close analogy between learning the English language and learning the C language.

The classical method of learning English is to first learn the alphabet used in the language, then learn to combine these alphabets used in the language, then learn to combine these alphabets to form words, which in turn are combined to form sentences, and sentences are combined to form paragraphs. Learning C is similar and easier. Instead of straight-away learning how to write programs, we must first know what alphabets, numbers, and special symbols are used in C, then how using them constants, variables, and keywords are constructed, and finally how are these combined to form an instruction. a group of instructions would be combined later on to form a program. this is illustrated in the below-given image.

Read Other tutorials

1. Basics of C Programming
2. The basic structure of the c program