C Programming Tutorial
Introduction to C
- 'C' is a programming language that was developed in the early 1970s by Dennis Ritchie at Bell Laboratories.
- It was designed for implementing system software and used for developing the portable application software.
- It is one of the most popular languages.
- C++ and Java are based on C programming which means that if you are well versed with C, then the above two programming languages can be learnt very easily.
- It is primarily used for the system programming. It has the portability, efficiency and the ability to access the specific hardware addresses and low runtime demand on system resources which makes it a good choice for implementation of operating systems and embed the system applications.
Characteristics of C
- C is a core language as many other programming labguages like C++, Java etc are based on it.
- C is a portable language because if we write a C program on one computer we can run it on another one without little or no modification.
- C is known as a robust language because it has a rich set of built-in functions and operators that help in writing complex programs.
- It is a stable language as it was created in 1983 and since then it has never been revised.
- It is a quick language as they make use of operators and data types which are fast and efficient.
- It is an extensible language as it helps the user to add his own functions to the C library.
- It is known as a structured language as the code is organized as a collection of one or more functions.
- It supports loose typing because a character here can be treated as an integer and vice versa.
- C has only 32 keywords which makes it easy to learn.
- Pointers are supported in C as they refer to the computer memory, array, structures and the functions.
- The features of assembly language and high-level language are combined by the C compiler.
- It is a high level programming language which enables the programmer for concentrating on the problem at hand and not worry about the machine code on which the program would run.
- There is an extensive usage of function calls.
- It is well suited for structured programming which enables the users to think of the problems in terms of functions/modules. It makes a complete program which in turn facilitates easy programming, debugging, testing and maintenance.
- It is widely used for implementing end-user applications.
Structure of a C program
They contain special instructions which indicate how the program is prepared for compilation. Common preprocessor command is 'include' that tells the compiler to execute a program where some information is required from the specified header file.
It is a variable/function which is declared after the preprocessor directives and before the main() function.
int add (int a, int b);
- A C program contains more than one function where the functions are defined together as a group and all the statements are executed together. The statements are written logically and in a sequence for performing certain tasks.
- The main() function is one of the most important parts of the program. It is a compulsory part of every C program.
- All the functions in the program which include the main() function are divided into two parts -
Declaration section: describes the data that will be used in the function.
Statement section: contains the code that will manipulate the data for specified tasks.
- A C program can have a number of functions depending on the number of tasks. Any number of statements can be included in the function.