C PROGRAMMING- LANGUAGE

 Now a day computer education is important part of our life. Computer is used in every field of life like Banking, Education , E-commerce, Internet etc,

C LANGUAGE - C PROGRAMMING 

Before starting c programming or c language lets understand what is the software and use .. 

Software is a collection of program or procedure to perform a particular task. And a program is a collection of instruction. To develop any software their is requirement of SDLC PROCESS called a Software Development Life Cycle. Their are different phase in SDLC PROCESS

SOFTWARE DEVELOPMENT LIFE CYCLE DIGRAM  

1-REQUIREMENT 

First We find what is the requirement of of user. what software or project he/she want to develop. what is his organization requirement.. what is the basic purpose of project. The requirement give the idea to the developer.

2-ANALYSIS

After requirement phase the developer  analyze how can  develop the software or project.. what kind of language or tool is required and how to make the database according to project. The developer ask question from user or search on internet according to requirement.

3-DESIGN 

After analyzing project we will start the design part. because it is the one of most important part of SOFTWARE DEVELOPMENT LIFE CYCLE . we use DFD or other tools to make the project design.. also create the data dictionary to valuate the flow of data.

4-CODING

now we start the coding part. both coding and design run together. first we select the language to develop the code it may be any programming language..

5-TESTING

After developing the software or project we test it whether it is working according to need or not. it play important role to check the user requirement .their are many method of testing like, 

System Testing, Structure Testing, Unit Testing ,alpha testing, beta testing.

C Language- (C Programming) Introduction

C is a procedural or a structure programming language. It was initially developed by Dennis Ritchie between 1972. It was mainly developed as a system programming language to write operating system to develop the UNIX Operating System. The main features of C language include low-level access to memory, simple set of keywords, and token,data type  features make C language suitable for system programming like operating system or compiler development.  C has capability of both middle and higher level language. 

To start any programming language we need some basic component of programming language .

A- DELIMITER 

Delimiter are the symbol which are used in programming language for different purpose.

# - for header files

{} - for block use 

() - for any function 

[]- for array

: - used in switch statement  

; - for termination of line

B- DATA TYPES IN C LANGUAGE

Every variable in C has an associated data type. Every data type which is used requires different amounts of memory and performs operations. There  are  examples of some  data types used in C:

int: according to  name it  is used to store an integer value. Like 10,30 . It require 2 byte of memory.

char: This is the  most basic data type in C. It stores a single character at one time  and requires a single byte of memory in almost all compilers.

float: this data type is used to store decimal numbers (numbers with floating point value) with single precision use.

double: It is used to store decimal numbers (numbers with floating point value) with double precision use.

C - VARIABLES AND KEYWORDS USED IN C

A variable in simple word  is a name which store some value and some memory allocated to it. So basically a variable used to store some form of data. Different types of variables require different amounts of memory depends on what type of data is there.

How To  Declare Variable:

Data  type variable_name;

For multiple variables Declartion:

 Data type variable1_name, variable2_name, variable3_name;

variable name can consist of alphabets (both upper and lower case), numbers and the underscore ‘_’ character. However, the name  not started   with a number.

DIFFERENCE B/W VARIABLE DECLARATION AND DEFINITION

Variable declaration refers to the part where a variable is first declared or introduced before its first use. Variable definition is the part where the variable is assigned a memory location and a value. Most of the times, variable declaration and definition are done together

Like int a=10; is a Definition or Initialization.

D-  CONST:

const keyword is used to declare constant variables. When we initialized Constant variables, we can’t change their value. constatnt value assigned to them is unmodifiable.

Syntax:

const data_type var_name = var_value;

Note: Constant variables need to be compulsorily be initialized during their declaration itself. The keyword const can used with pointers.

USE BOOL IN C

CAN APPLY WITH : Bool Data Type in C++

The C99 standard for C language supports bool variables. Unlike C++, Theare is  no header file needed to use bool, a header file “stdbool.h” must be included to use bool in C.don’t save the program with .c extension , it will not compile, but if we save it as .cpp, it will work fine.

Example ; with form of array .

int main()

{

  bool arr[2] = {true, false};

  return 0;

}

E- INPUT/OUTPUT

Their is some function in c which is used for input and output..

PRINTF()-  

This funtion is used to give output on the screen.to print any message or value in c on the output device(monitor)..

• Syntax is - 
• printf("hello who r u");
• printf("%d",a); LET a is a variable of int type. int a=10;
• printf("value of a=%d",a);

SCANF()- 

This function is used for input . to read any value or any string such as integer ,char ,float from input device (keyboard) we use this function.

Syntax.

1. scanf("%d",&a) - let a is variable of int type.
2. scanf("%c",&b) - let b is variable of char type.

F-  Arithmetic Operators

An arithmetic operator perform airthmetic operations such as addition +, subtraction -, multiplication *, division / etc on numerical values (constants and variables)..

like - int a=10,b=20,c; c=a+b; printf("Sum is=%d", c);

G- Increment and Decrement Operators

Their is two programming operators in c language increment ++ and decrement -- to change the value of an operand by 1.
Increment ++operator  increases the value by 1 whereas decrement operator -- decreases the value by 1. These two operators are unary operators, meaning they only operate on a single operand.

1- For exmp Preincrement: 

int a=5,b;

b=++a;

printf("Value of a=%d",a)

printf("Value of b=%d",b)

Result is => a=6 and b=6;

2- Postincrement

int a=5,b;

b=a++;

printf("Value of a=%d",a)

printf("Value of b=%d",b)

Result is => a=7 and b=6;