C-Programming Language 

                                                                                                                     Program

• Set of instructions that tells a computer how to perform a particular task.
• They are developed by using programming language.

                                                                                                                     Software: 

• It refers to a program or set of instructions that instructs a computer to perform some tasks.
• They are classified into two classes.
  • System Software: Includes OS & various devices software's.
  • Application Software: Ms-Word, tally, C Compiler, etc.

                                                                                                                    Programmer:

• A person who writes a program using a programming language.
• Computer Programming: 
• It is a art of developing computer program.

                                                                                                         C-Programming 

• It is a general- purpose programming language.
• It is used for writing programs.
• It is a high level programming language and easy to learn. 
• It is possible to design Operating System, drivers, compilers, etc.
• Almost most of the programming languages like Java, C++, etc. follow C programming syntax. 

                                                                                Features of C-Programming 

• Easy to Learn & Understand.
• Machine independent.
• Faster Execution.
• Extensible.
• Reusuable.

                                                                              Structure of C-Programming 

• #include<stdio.h>
• #include<conio.h>
• Int main() {
• Printf(“Hello World \n Hello Ram Singh”);
• return 0;
• }

-------------------------------------------------------------

• #include<stdio.h>
• #include<conio.h> */ No need to write this /*
• Int main()
• {
• Int x=5; // Variable Decleration
• Printf(“Value of x=%d”, x);
• }

----------------------------------------------------------------

                                                                                                          Header Files

• It contains definitions of functions and variables, which is imported or used into any C program by using the pre-processor #include statement. 
• Header file have extension “.h” which contains C function declaration and macro definition. 
• Each header file contains information ( or declarations) for a particular group of functions. 
• Like stdio.h header file contains declaration of standard input and output functions available in C which is used for get the input and print the output.
• Similarly, the header file math.h contains declarations of mathematical functions available in C. 

                                                                                                    C Preprocessor files

• Preprocessor directives are the grammar of C. 
• It is used for handling source file and macro definitions in the program.

                                                                                Comments in C Programming Language

• In C , we can declare comments in two ways:
• 1. Single Line Comment: If we want to place only one line of comment somewhere in program, we can write comment after double forward slashes (//). It does not have ending slashes. For Example: // This is just testing.
• 2. Block Comment/ Multi Line Comment: If we want to place some blocks of comments in a program, we can write comment starting by forward slash asterisk (/*) and write multiple lines of comment and ending with asterisk forward slash (*/).  This Comment has starting as well as ending portion. For Example: 
• /* This is just for testing
• It takes two values,
• And generates greatest number. 
• */

                                                                                      Identifiers, Keywords and Tokens

• Identifier: A name which is given by user it is known as Identifier. 
• Keywords: It is a reserved word which have fixed meaning.
  • There are 32 keywords in C language.
• Tokens: The basic element recognized by the compiler is known as Tokens.

Basic Data Types in C

• There are 2 types of data types in C. They can be classified as:

1. Primary Data Types

• Char,
• Int,
• Float,
• Double,
• Void

2. Secondary Data Types

-Array,

-Pointer,

-Structure,

-Union,

-Enum

                                                                                    Types of specifier 

• The type of data to be printed on standard output is called Specifier. Some of the mostly used specifier are:
• 1. Escape Specifier,
• 2. Format Specifier.

                                                                                            Variable

• A name which can store a value.
• We can re-use that value using of variable.
• For e.g.: Book name is a variable and book price is a value. 

                                                                        Variable Declaration & Initialization

• Type variable name;     int. a, b;
• Initialization e.g. :
•    a=10; b=20;
• Note: Comma is used to separation.

                                                                                                 Variable Declaration rules

• A variable name can have alphabets, digits and underscore.
• E.g. : int a;
• Variable name can start with alphabets and underscore only.
• Variable name cannot be start with digits.
•    Whitespace is not allowed in variable name. eg: int student marks;
• A variable name must not be any reserved word or keyword. Eg: int float;   
• But we can write int INT; 

                                                                                              Practice of Variable

• #include<stdio.h>
• #include<conio.h>
• Int main() 
• {

Int a;

a=10;

Printf(“the value of a =%d”, a);

Printf(“a=%d”, a);

Return 0;

}

Define /n also for line break

                                                                                                         Constant

• A Constant is a fixed value which cannot be changed during the program execution.

                                                                                          Operators and Expressions

• A operator is a sign or symbol, which performs an operation or evaluation on one or more operands.
• Operands are values or variables dclare within program. For example: 5+10 where ‘+’ sign is an operator and 5 and 10 are operands.

                                                                                        Types of Operator used in C

• Arithmetic Operators,
• Logical Operators,
• Assignment Operators,
• Conditional Operators,
• Bitwise Operators,
• Comma Operators,
• Increment/ Decrement Operators,
• Ternary Operator.

                                                                                     Input/ Output  (I/O) Functions 

• C provides the following Input/output functions.
  • Formatted I/O functions,
  • Unformatted I/O functions.

                                                                    Some of the formatted I/O function are as follows:

• Some of the unformatted input output functions are:
   

                                                                                                    Control Statement

• It is a way to control a program through control statements.
• There are three types of control statements which control the flow of program.
  • Conditional Statement
  • Looping Statements
  • Jumping Statements.

                                                                                                 Conditional Statement

• Conditional Statements:
  • Decision Structure:
    • It is used to make selection.
    • Selection allows us to choose option from two or more options available within the program.
    • There are two types of selection statements.
      • Two-Way Selection,
      • Multi-Way Selection.

                                                                                          Types Conditional Statement

• 1. The Simple If Statement,
• 2. The If-Else Statement,
• 3. The Else If Ladder Statement,
• Nested If Statement,
• Switch Statement.

                                                                                          The Simple IF Statement