C language Tutorials-Variables and Data Types

The Data what be store can be classify as follows.

--> Variable is just a memory location which is capable of storing some data.

--> Datatype represent characteristic properties of a variable i.e the type of value to store and the amount of memory required.

--> So, the datatype provides a "C" language are as follows.

1) char (1 byte)

2) int (2 bytes)

3) float (4 bytes)

4) double (8 bytes)

--> The Keywords short, long, signed, unsigned are referred as Type Qualifiers. Because they specify/qualify the properties of datatype.

--> The Keywords short, long are in general referred as Size Qualifiers.

--> The Keywords signed, unsigned are referred as Sign Qualifiers.

--> When we don't specify any qualifiers, then by default it is considered as short and signed.

signed char ( 1 byte ):

1

1

1

1

1

1

1

        MSB <---- 7     6        5       4       3       2      1      0  ---->LSB

Range:  -128  to  +127

unsigned char( 1 byte ):

Range: 0 to 255

--> When we have n bits, the range of signed type will be -2^n-1 to +2^n-1-1 and for unsigned type will be 0 to 2ⁿ-1

Example:-

signed char ---> 8 bits ---> -2⁷ to +2⁷-1
                                    ---> -128 to +127

unsigned char ----> 8 bits ---> 0 to 2⁸-1
                                                 0 to 255

short signed int ----> 2 bytes ---> 16 bits ---> -2¹⁵ to 2¹⁵-1
                                                                         -32768 to 32767

short unsigned int ----> 2 bytes ---> 16 bits ---> 0 to 2¹⁶-1
                                                                             0 to 65535

long signed int ----> 4 bytes ---> 32 bits ---> -2³¹ to 2³¹-1
                                                                        -2147483648 to 2147483647

long unsigned int ---> 4 bytes ---> 32 bits ---> 0 to 2³² -1
                                                                           0 to 4294967296

float ( 4 bytes):

            Here the data will be stored in Mantissa and Exponent format.

--> Here we can store a maximum of 6 digits only in the functional part.

--> Similarly double type required 8 bytes.

--> Memory will not be allocated for a datatype.

--> Memory will allocated only for a variable.

--> So, we can't stored data in a datatype, but we can store data only in a variable

--> A Variable can't be access unless we declare it.

--> The syntax for declaring a variable is as follows.

              datatype <variable name> [= value]

--> When we declare a variable, memory will be allocated for the corresponding number of bytes and initially it contains some dummy value and is referred as garbage value.

Example:- Declaration:
                     

---> We can also specify the value to be placed in a variable at the time of declaration itself and it is referred as initialization.

Example:- Initialization:

---> The value contained in a  variable can be changed/modified as required the assigning the necessary value and it is referred as assignment

Example:-  Assignment:

---> When we are required to display a direct value or the value contained in a variable or the result contained in a variable or the result of an expression, we should specify the type specifiers in  the format.

---> Some of the type specifiers are as follows.

%c                          --------->  Character

%i (or) %d             --------->  integer

%f                          --------->  float

%g                         --------->   double

%li (or) %ld           --------->  long integer

%lf                         --------->  long float

%lg                        --------->  long double 

%u                         --------->  unsigned

---> The symbol % represents unknown value or blank, which will be filled later

---> The symbol next do % specify the type of value to be filled in that blank

---> The value to be filled in that blank should be specified after the format.

Example:-

               #include<stdio.h>

               #include<conio.h>

               void main( )

               {

                        int x;

                        x = 56;

                        printf("%i", x);

                }

Output:-

          56       

---> The output is to be displayed in the most possible stylish way.