Learning-C

4. Numeric Constants and Variables

Variables

A quantity which may vary during program execution is called variable. Each Variable stres in different memory location.There are multiple types of variable present in C. Look into the table.

S/L	Assign	Printing	Maximum Size (32-bit / 64-bit)
1	int	%d	2,147,483,647 / 2,147,483,647
2	unsigned int	%u	4,294,967,295 / 4,294,967,295
3	long int	%ld	2,147,483,647 / 9,223,372,036,854,775,807
4	unsigned long int	%lu	4,294,967,295 / 18,446,744,073,709,551,615
5	long long int	%lld	9,223,372,036,854,775,807 / 9,223,372,036,854,775,807
6	unsigned long long int	%llu	18,446,744,073,709,551,615 / 18,446,744,073,709,551,615
7	float	%f	3.4E+38 / 3.4E+38
8	short	%hd	32,767 / 32,767
9	double	%lf	1.7E+308 / 1.7E+308
10	long double	%Lf	1.2E+4932 / 1.2E+4932
11	decimal integer	%d	2,147,483,647 / 2,147,483,647
12	octal integer	%o	4,294,967,295 / 4,294,967,295
13	hexadecimal integer	%x	4,294,967,295 / 4,294,967,295
14	Character	%c
15	String	%s

See the below code where I have assign different type variable and then print the value.

\n include create a new line in standard output.

Downl.oad Code

/* In this programe we just declare a variable assign the value
*  Then print the value of corresponding variable content value.
*/

#include<stdio.h>


int main(){

    //Integer types variable
    int integer = -34;
    printf("The value of integer is %d\n", integer);

    unsigned int unsigned_integer =  67; //if we try to use -67 then the variable store highest positive number
    printf("The value of unsigned_integer is %u\n", unsigned_integer);

    short short_int = 2567;
    printf("The value of short_int is %d\n", short_int);

    long long_integer = -123456789L;
    printf("The value of long_integer is %ld\n", long_integer);

    unsigned long unsigned_long_integer = 123456789UL; //if we try to use -123456789LU then the variable store highest positive number
    printf("The value of unsigned_long_integer is %lu\n", unsigned_long_integer);

    long long long_long_integer = -98123456789LL; 
    printf("The value of unsigned_long_integer is %lld\n", long_long_integer);

    unsigned long long unsigned_long_long_integer = 98123456789LL; //if we try to use -98123456789LL then the variable store highest positive number
    printf("The value of unsigned_long_integer is %llu\n", unsigned_long_long_integer);

    //-----------------------------------------------------------------------------------
    //Floating point type variables
    float float_val = -256.980568967;
    printf("The value of float_val is %0.5f\n", float_val); //The value of float_val is -256.98056

    double double_val = 5678900074.567907890045;
    printf("The value of double_val is %lf\n", double_val);

    long double long_double_val = 5678900074.567907890045;
    printf("The value of long_double_val is %Lf\n", long_double_val);


    //-----------------------------------------------------------------------------------
    int octalVar = 052; // Octal variable (leading 0 indicates octal)
    printf("Octal: %o (decimal: %d)\n", octalVar, octalVar); // Printing the octal variable and corresponding decimal number

    int hexVar = 0x2A; // Hexadecimal variable (0x indicates hex)
    printf("Hexadecimal: %x (decimal: %d)\n", hexVar, hexVar); // Printing the hexadecimal variable and corresponding decimal number

    //-------------------
    //Character variable assigne its value by single quote ''
    char my_char = 'a';
    printf("The value of my_char = %c\n", my_char); //Output : The value of my_char =  'a'

    //String
    //String is array of multiple character
    //String variable assign by double quote ""
    my_string[] = "abra ca dabra";
    printf("The value of my_string = %s\n", my_string); //The value of my_string = abra ca dabra

}

Output

The value of integer is -34
The value of unsigned_integer is 67
The value of short_int is 2567
The value of long_integer is -123456789
The value of unsigned_long_integer is 123456789
The value of unsigned_long_integer is -98123456789
The value of unsigned_long_integer is 98123456789
The value of float_val is -256.98056
The value of double_val is 5678900074.567908
The value of long_double_val is 5678900074.567908
Octal: 52 (decimal: 42)
Hexadecimal: 2a (decimal: 42)
The value of my_char = a
The value of my_string = abra ca dabra

Numeric Constant

The constants are never change during the execution of the programme.We can assign constants by using#define parameter. Look the below program example.

Download Code

#include<stdio.h>

#define PI 3.1415927
#define MAX_RANGE 100
#define MIN_RANGE 0

int main(){

    prinntf("The Value of PI is %f", PI);
}

Output

The Value of PI is 3.141593