C Programming Language Tutorial - GeeksforGeeks (2024)

In thisC Tutorial, you’ll learn all C programming basic to advanced concepts like variables, arrays, pointers, strings, loops, etc. This C Programming Tutorial is designed for both beginners as well as experienced professionals, who’re looking to learn and enhance their knowledge of the C programming language.

What is C?

C is a general-purpose, procedural, high-level programming language used in the development of computer software and applications, system programming, games, and more.

• C language was developed byDennis M. Ritchieat the Bell Telephone Laboratories in1972.
• It is a powerful and flexible language which was first developed for the programming of theUNIX operating System.
• C is one of the most widely used programming languages.

C programming languageis known for its simplicity and efficiency. It is the best choice to start with programming as it gives you a foundational understanding of programming.

Getting Started With C Tutorial

Start your coding adventure with our free C Tutorial. A perfect C programming tutorial for beginners and advanced coders alike, this tutorial is your key to unlocking the magic of C programming. With clear explanations and fun examples.

C Basics

• C Language Introduction
• Features of C Programming Language
• C Programming Language Standard
• Setting Up C Development Environment
• C Hello World Program
• Compiling a C Program: Behind the Scenes
• C Comments
• Tokens in C
• C Identifiers
• Keywords in C

C Variables and Constants

• C Variables
• Constants in C
• Const Qualifier in C
• Different Ways to Declare Variable as Constant in C
• Scope Rules in C
• Internal Linkage and External Linkage in C
• Global Variables in C

C Data Types

• Data Types in C
• Data Type Modifiers in C
• Literals in C
• Escape Sequence in C
• bool in C
• Integer Promotions in C
• Character Arithmetic in C
• Type Conversion in C

C Input/Output

• Basic Input and Output in C
• Format Specifiers in C
• printf in C
• scanf in C
• Scansets in C
• Formatted and Unformatted Input and Output Functions

C Operators

• Operators in C
• Arithmetic Operators in C
• Unary Operators in C
• Relational Operators in C
• Bitwise Operators in C
• Logical Operators in C
• Assignment Operators in C
• Increment and Decrement Operators in C
• Conditional or Ternary Operator (?:) in C
• size of Operator in C
• Operator Precedence and Associativity in C

CControl Statements Decision-Making

• Decision-Making in C
• C if Statement
• C if…else Statement
• C if-else-if Ladder
• Switch Statement in C
• Using Range in switch case in C
• Loops in C
• C for Loop
• while looping in C
• do…while Loop in C
• for versus while Loop
• continue Statement in C
• break Statement in C
• goto Statement in C

C Functions

• C Functions
• User-Defined Function in C
• Parameter Passing Techniques in C
• Importance of Function Prototype in C
• Return Multiple Values From a Function
• main Function in C
• Implicit Return Type int in C
• Callbacks in C
• Nested Functions in C
• Variadic functions in C
• _Noreturn Function Specifier in C
• Predefined Identifier __func__ in C
• Maths Functions in C

C Arrays & Strings

• C Arrays
• Properties of Array in C
• Multidimensional Arrays in C
• Initialization of Multidimensional Arrays in C
• Pass Array to Functions in C
• Pass a 2D Array as a Parameter in C
• Data Types for Which Array is Not Possible
• Pass an Array by Value in C
• Strings in C
• An Array of Strings in C
• Difference Between Single Quoted and Double Quoted Initialization
• String Functions in C

C Pointers

• C Pointers
• Pointer Arithmetics in C
• Pointer to Pointer (Double Pointer) in C
• Function Pointer in C
• Declare Function Pointer in C
• Pointer to an Array in C
• Constant Pointer in C
• Pointer vs Array in C
• Dangling, Void, Null and Wild Pointers
• Near, Far and Huge Pointers in C
• restrict Keyword in C

C User-Defined Data Types

• C Structures
• dot (.) Operator in C
• C typedef
• Structure Member Alignment, Padding and Data Packing
• Flexible Array Members in a Structure in C
• C Unions
• Bit Fields in C
• Difference Between Structure and Union in C
• Anonymous Union and Structure in C
• Enumeration (or enum) in C

C Storage Classes

• Storage Classes in C
• extern Keyword in C
• Static Variables in C
• Initialization of Static Variables in C
• Static Functions in C
• Understanding “volatile” Qualifier in C
• Understanding the “register” Keyword in C

C Memory Management

• Memory Layout of C Programs
• Dynamic Memory Allocation in C
• Difference Between malloc() and calloc()
• What is a Memory Leak?
• Dynamic Array in C
• Dynamically Allocate a 2D Array in C
• Dynamically Growing Array in C

C Preprocessor

• C Preprocessors
• C Preprocessor Directives
• How a Preprocessor Works in C?
• Header Files in C
• Difference Between Header Files “stdio.h” and “stdlib.h”
• Write Your Own Header File in C
• Macros and their Types in C
• Interesting Facts About Macros and Preprocessors in C
• # and ## Operators in C
• Print a Variable Name in C
• Multiline Macros in C
• Variable Length Arguments for Macros
• Branch Prediction Macros in GCC
• typedef versus #define in C
• Difference Between #define and const in C

C File Handling

• Basics of File Handling in C
• C fopen() Function
• EOF, getc() and feof() in C
• fgets() and gets() in C
• fseek() vs rewind() in C
• Return Type of getchar(), fgetc() and getc()
• Read/Write Structure From/to a File in C
• C Program to Print Contents of File
• C Program to Delete a File
• C Program to Merge Contents of Two Files into a Third File
• Difference Between printf, sprintf and fprintf
• Difference Between getc(), getchar(), getch() and getche()

C Error Handling

• Error Handling in C
• Using goto for Exception Handling in C
• Error Handling During File Operations in C
• C Program to Handle Divide By Zero and Multiple Exceptions

C Programs

• Basic C Programs
• Control Flow Programs
• Pattern Printing Programs
• Functions Programs
• Arrays Programs
• Strings Programs
• Conversions Programs
• Pointers Programs
• Structures and Unions Programs
• File I/O Programs
• Date and Time Programs
• More C Programs

Miscellaneous

• Date and Time in C
• Input-output system calls in C
• Signals in C
• Program Error Signals in C
• Socket Programming in C
• _Generics Keyword in C
• Multithreading in C

C Interview Questions

• Top 50 C Programming Interview Questions and Answers
• Commonly Asked C Programming Interview Questions | Set 1
• Commonly Asked C Programming Interview Questions | Set 2
• Commonly Asked C Programming Interview Questions | Set 3

Why Learn C?

C programming language is one of the most popular programming language. It is a must learn for software engineering students. C is called the mother of all modern programming languages so learning C will help you to learn other languages easily like Java, C++, C#, Python, etc. C language is faster than other programming languages like Java and Python. It can handle low-level programming and we can compile the C code in a variety of computer platforms.

List of somekey advantages of C language:

• Easy to learn.
• Versatile Language, which can be used in both applications and technologies.
• Mid-Level Programming Language.
• Structured Programming Language.

C Compiler

C compiler is a software that translates human-readable C language code into machine code or an intermediate code that can be executed by a computer’s central processing unit (CPU).

There are manyC compilersavailable in the market, such asGNU Compiler Collection (GCC),Microsoft Visual C++ Compiler,Clang,Intel C++ Compiler, andTinyCC (TCC).

For this tutorial, we will be using the GNU-based online C compiler provided by GeeksforGeeks which is developed for beginners and is very easy to use compared to other compiler/IDE’s available on the web.

Print Hello World using C Programming

#include <stdio.h> int main() {printf("Hello World! I Don't Give a Bug");return 0;}

Output

Hello World! I Don't Give a Bug

“Give this C code a try, and here’s a fun challenge: print ‘Hello World’ along with your name!”

Features of C Language

There are some key features of C language that show the ability and power of C language:

• Simplicity and Efficiency:The simple syntax and structured approach make the C language easy to learn.
• Fast Speed:C is one of the fastest programming language because C is a static programming language, which is faster than dynamic languages like Java and Python. C is also a compiler-based which is the reason for faster code compilation and execution.
• Portable:C provides the feature that you write code once and run it anywhere on any computer. It shows the machine-independent nature of the C language.
• Memory Management:C provides lower level memory management using pointers and functions like realloc(), free(), etc.
• Pointers:C comes with pointers. Through pointers, we can directly access or interact with the memory. We can initialize a pointer as an array, variables, etc.
• Structured Language:C provides the features of structural programming that allows you to code into different parts using functions which can be stored as libraries for reusability.

Applications of C Language

C was used in programs that were used in making operating systems. C was known as a system development language because the code written in C runs as fast as the code written in assembly language.

The use of C is given below:

• Operating Systems
• Language Compilers
• Assemblers
• Text Editors
• Print Spoolers
• Network Drivers
• Modern Programs
• Databases
• Language Interpreters
• Utilities

FAQs on C Language

Q1. How to learn C easily?

Answer:

The first steps towards learning C or any language are to write a hello world program. It gives the understanding of how to write and execute a code. After this, learn the following:

• Variables
• Operators
• Conditionals
• Loops and Errors
• Arrays and Strings
• Pointers and Memory
• Functions
• Structures
• Recursions

Q2. Difference between C and C++?

Answer:

Q3. Is C easy to learn for beginners?

Answer:

While C is one of the easy languages, it is still a good first language choice to start with because almost all programming languages are implemented in it. It means that once you learn C language, it’ll be easy to learn more languages like C++, Java, and C#.

Q4. Why should we learn C first rather than C++?

Answer:

C is a ‘mother of all languages.’ It provides a solid understanding of fundamental programming concepts and is considered easier to grasp. C offers versatile applications, from software development to game programming, making it an excellent choice for building a strong programming foundation.