Learn C programme. C Programming language. Cloud1 C tutorial

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1 Learn C programme C Programming language Cloud1 C tutorial

2 About The Tutorial C is a general-purpose, procedural, imperative computer programming language developed in 1972 by Dennis M. Ritchie at the Bell Telephone Laboratories to develop the UNIX operating system. C is the most widely used computer language. It keeps fluctuating at number one scale of popularity along with Java programming language, which is also equally popular and most widely used among modern software programmers. Audience This tutorial is designed for software programmers with a need to understand the C programming language starting from scratch. This tutorial will give you enough understanding on C programming language from where you can take yourself to higher level of expertise. Prerequisites Before proceeding with this tutorial, you should have a basic understanding of Computer Programming terminologies. A basic understanding of any of the programming languages will help you in understanding the C programming concepts and move fast on the learning track. Copyright & Disclaimer All the content and graphics published in this e-book are the property of Tutorials Point (I) Pvt. Ltd. The user of this e-book is prohibited to reuse, retain, copy, distribute or republish any contents or a part of contents of this e-book in any manner without written consent of the publisher. We strive to update the contents of our website and tutorials as timely and as precisely as possible, however, the contents may contain inaccuracies or errors. Tutorials Point (I) Pvt. Ltd. provides no guarantee regarding the accuracy, timeliness or completeness of our website or its contents including this tutorial. If you discover any errors on our website or in this tutorial, please notify us at info@cloud1.me i

3 Table of Contents About The Tutorial... i Audience... i Prerequisites... i Copyright & Disclaimer... i Table of Contents... ii 1. OVERVIEW...1 Facts about C... 1 Why Use C?... 1 C Programs ENVIORNMENT SETUP...3 Try it Option Online... 3 Local Environment Setup... 3 Text Editor... 3 The C Compiler... 4 Installation on UNIX/Linux... 4 Installation on Mac OS... 5 Installation on Windows PROGRAM STRUCTURE...6 Hello World Example... 6 Compile and Execute C Program BASIC SYNTAX...8 Tokens in C... 8 Semicolons... 8 Comments... 8 Identifiers... 9 ii

4 Keywords... 9 Whitespace in C DATA TYPES...11 Integer Types Floating-Point Types The void Type VARIABLES...15 Variable Definition in C Variable Declaration in C Lvalues and Rvalues in C CONSTANTS AND LITERALS...19 Integer Literals Floating-point Literals Character Constants String Literals Defining Constants The #define Preprocessor The const Keyword STORAGE CLASSES...24 The auto Storage Class The register Storage Class The static Storage Class The extern Storage Class OPERATORS...28 Arithmetic Operators Relational Operators iii

5 Logical Operators Bitwise Operators Assignment Operators Misc Operators sizeof & ternary Operators Precedence in C DECISION MAKING...45 if Statement if else Statement if..else if.. else Statement Nested if Statements switch Statement Nested switch Statements The? : Operator: LOOPS...58 while Loop for Loop do while Loop Nested Loops Loop Control Statements break Statement continue Statement goto Statement The Infinite Loop FUNCTIONS...76 Defining a Function Function Declarations iv

6 Calling a Function Function Arguments Call by Value Call by Reference SCOPE RULES...84 Local Variables Global Variables Formal Parameters Initializing Local and Global Variables ARRAYS...89 Declaring Arrays Initializing Arrays Accessing Array Elements Arrays in Detail Multidimensional Arrays Two-dimensional Arrays Initializing Two-Dimensional Arrays Accessing Two-Dimensional Array Elements Passing Arrays to Functions Return Array from a Function Pointer to an Array POINTERS What are Pointers? How to Use Pointers? NULL Pointers Pointers in Detail Pointer Arithmetic Incrementing a Pointer v

7 Decrementing a Pointer Pointer Comparisons Array of Pointers Pointer to Pointer Passing Pointers to Functions Return Pointer from Functions STRINGS STRUCTURES Defining a Structure Accessing Structure Members Structures as Function Arguments Pointers to Structures Bit Fields UNIONS Defining a Union Accessing Union Members BIT FIELDS Bit Field Declaration TYPEDEF typedef vs #define INPUT AND OUTPUT The Standard Files The getchar() and putchar() Functions The gets() and puts() Functions The scanf() and printf() Functions FILE I/O vi

8 Opening Files Closing a File Writing a File Reading a File Binary I/O Functions PREPROCESSORS Preprocessors Examples Predefined Macros Preprocessor Operators The Macro Continuation (\) Operator The Stringize (#) Operator The Token Pasting (##) Operator The Defined() Operator Parameterized Macros HEADER FILES Include Syntax Include Operation Once-Only Headers Computed Includes TYPE CASTING Integer Promotion Usual Arithmetic Conversion ERROR HANDLING errno, perror(), and strerror() Divide by Zero Errors Program Exit Status vii

9 27. RECURSION Number Factorial Fibonacci Series VARIABLE ARGUMENTS MEMORY MANAGEMENT Allocating Memory Dynamically Resizing and Releasing Memory COMMAND LINE ARGUMENTS...174

10 About the Author Destiny drew Cloud1 Web Solutions towards computers when the IT industry was just making a beginning in India. Cloud1 Web Solutions has a passion for writing and is an author of several books in C, C++, VC++, C#,.NET, DirectX and COM programming. He is a much sought after speaker on various technology subjects and is a regular columnist for Express Computers and Developer 2.0. His current affiliations include being a Director of KICIT, a training company and DCube Software Technologies, a software development company. In recognition to his contribution Microsoft awarded him the prestigious Best.NET Technical Contributor award recently. He can be reached at cloud1.me. viii

1. OVERVIEW C Programming What is C C is a programming language developed at AT & T s Bell Laboratories of USA in 1972. It was designed and written by a man named Dennis Ritchie.

11 1. OVERVIEW C Programming What is C C is a programming language developed at AT & T s Bell Laboratories of USA in 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 is 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 superceded by languages like C++, C# and Java, so why bother to learn C today. I seriously beg to differ with this opinion. There are several reasons for this:

12 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. do 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 very thoroughly using C language before migrating to C++, C# or Java. Though this two step learning process may take more time, but at the end of it you will definitely find it worth the trouble. C++, C# or Java make 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, Linux is 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.

13 Mobile devices like cellular phones and palmtops are becoming increasingly popular. Also, common consumer devices like microwave oven, 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 this devices. These programs not only have to run fast but also have to work in 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 won't become popular if they takes 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 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 the very important step in your quest for learning programming languages.

C-LANGUAGE CURRICULAM

C-LANGUAGE CURRICULAM Duration: 2 Months. 1. Introducing C 1.1 History of C Origin Standardization C-Based Languages 1.2 Strengths and Weaknesses Of C Strengths Weaknesses Effective Use of C 2. C Fundamentals