Day 3 : Variable and Data types in the C language.

In last session we discuss about below points.

1. What is Comments in c lang?

we have mainly two types of commenting in c language.

a.Single line comment

Single line comments are represented by "//".

single line comments are used to comments single line in c language.

b.Multi line comments

Multiline comments are represented by "/* ----------*/".

Multiline commenting are used to comments more than one line in c language.

2. Datatypes & identifiers in c lang?

Datatypes are data represented in c language for different values in c lang . Identifiers .

3. Keywords in c lang

Keywords are reserved keyword in c lang .

4. What is white space in c-lang?

white space is ignored by c lang compilar.

5. Input And Output Functions in c lang?

Input Functions :

Input Functions are functions in which user can input value.

Output Functions:

Output Functions are functions in which we can print our output value in our compiler.

Please Read Privious Chapter In c-lang: Day 2 : Structure of c and Input , Output in c programming

***********Varibales & Datatypes in c*************

What is variables in c lang?

variable declaration is important for print values or more complex equations.

variable is only name for storage are that our programe can set.

What are the laws in c lang for variable declaration?

we can not use keyword(reserve keywords) as variable name;
can containt alphabets, digits, underscore.
can't start with a digit. /// int One
white space and rezerved keyword is not allowed.

Valid Example for variable declaration:

int one = 1;

char one = 'a';

Invalid Example for variable declaration:

int 121one = 1;

char 1 = 'a';

//Single character declaration in c

char name = 's';

//string declaration in c

char name[] = "Learn";

//intiger declaration

int name = 12;

//floting value declaration

float name = 10.50;

Datatypes in c language

datatypes specifies the size & type of value that can be stored as an variable.

1) Basic Data type

int = { 2 byte & -32768 to 32767}
char = { 1 byte & -128 to 127}
float = { 4 byte & }
double = { 8 byte }

// we Can cheack sizes of data type in c lang with sizeof function .

Small assignment for everybody: Print Size of int , char , float in dev C++;

2) Derived Data type //depending upon project

Array
Pointer
structure
union

3) Enumeration Data type: enum

4) Void Data type: void // empty

More information for c lang

Datatype size by 32 bit architecture
find size of data type in your programm with
printf(" size of int :%d" , sizeof(int));
data types consume memory / ram of from your system.
Example with 4 gb ram
-----> bits to Gb conversion

Assaignment of the day?

Program 1: WAP to display first name, middle name, last name and scored marks, grades of candidates who participated in a quiz competition using formatted output.
Program 2: WAP to display the list of at least 5 fruits and their quantities with unit price.
Program 3. WAP to display name of your friend, date of birth and city, where output should be formatted properly
Program 4. WAP to display the well formatted output to list the order details contains order id, order date, customer name, contact no, due amount