/* syntax of a variable declaration in C */
Type identifier; /* declaration of a single variable */
Type identifier_1 identifier_2 identifier_N; /* declaration of multiple variables with the same Type */

/* example of valid identifiers */
sum 
flag
i
Sum
mem_alloc
x5j6
SUM
/* examples of invalid identifiers */
sum$value /* $ is not a valid character */
piece flag /* Embedded spaces are not supported */
3spencer /* identifier cannot start with a number */
int /* int is a keyword in C */

/* examples of variable declaration */
int height;
float profit;

/* examples of variable declaration */
int height;
float profit;

/* initialize the variables */
height = 8;
profit = 21.50;

1 Byte = 8 Bits

#include <stdio.h>
/**
 * main - Entry point of the program 
 * Description: Program will print the memory allocation specification 
 * for each of the C fundamental types using   
 * 
 * Return: 0 if program successfully executes
 */

int main(void)
{
    /* print the size of the C fundamental types */
    printf("Size of type 'char' on my computer is: %lu bytes\n," sizeof(char));
    printf("Size of type 'int' on my computer is: %lu bytes\n", sizeof(int));
    printf("Size of type 'float' on my computer is %lu bytes\n", sizeof(float));

    return (0);
}

/* examples of valid integer constants */
10
255
11000

/* example of valid octal integer constants */
017
0377
077777

/* examples of valid hexidecimal integer constants */
0xff
0xfF
0x1A
0xAB

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
/**
 * main - Entry point of the program 
 * Description: Program will assign a random number to a variable and print it 
 * whether the number stored in the variable is positive or negative followed by
 * a new line.
 * 
 * Return: 0 if program successfully executes
 */

int main(void)
{
    /* variable declaration */
    int n;

    /* assign random number to variable n */
    srand(time(0));
    n = rand() - RAND_MAX / 2;

    /* check if number assigned to the variable n is positive or negative */
    if (n < 0)
    {
        printf("%d is negative\n", n);
    } else if (n == 0)
    {
        printf("%d is zero\n", n);
    } else
    {
        printf("%d is positive\n", n);
    }

     /* exit program after successful execution */
    return (0);
}

#include <stdio.h>
#include <limits.h>
/**
 * main - Entry point of the program 
 * Description: Program will print the range values for each integer type
 * 
 * Return: 0 if program successfully executes
 */
int main(void)
{
    /* variable declaration */
    int integerVarMin;
    int integerVarMax;
    unsigned int uIntegerVarMax;
    short sIntegerVarMin;
    short sIntegerVarMax;
    unsigned short u_sIntegerVarMax;
    long LIntegerVarMin;
    long LIntegerVarMax;
    unsigned long u_LIntegerVarMax;


    /* Assign to each variable the macros defined 
     * for their integer type in the limits.h header 
     */ 
    integerVarMin = INT_MIN;
    integerVarMax = INT_MAX;
    uIntegerVarMax = UINT_MAX;
    sIntegerVarMin = SHRT_MIN;
    sIntegerVarMax = SHRT_MAX;
    u_sIntegerVarMax = USHRT_MAX;
    LIntegerVarMin = LONG_MIN;
    LIntegerVarMax = LONG_MAX;
    u_LIntegerVarMax = ULONG_MAX;

    /* Use printf and format specifiers to print values stored in each variable */
    printf("The min value that can be stored in an INT variable is: %d\n", integerVarMin);
    printf("The max value that can be stored in an INT variable is: %d\n", integerVarMax);
    printf("The max value that can be stored in an UNSIGNED INT variable is: %u\n", uIntegerVarMax);
    printf("The min value that can be stored in a SHORT INT variable is: %hd\n", sIntegerVarMin);
    printf("The max value that can be stored in a SHORT INT variable is: %hd\n", sIntegerVarMax);
    printf("The max value that can be stored in an UNSIGNED SHORT INT variable is: %hu\n", u_sIntegerVarMax);
    printf("The min value that can be stored in an LONG INT variable is: %ld\n", LIntegerVarMin);
    printf("The max value that can be stored in an LONG INT variable is: %ld\n", LIntegerVarMax);
    printf("The max value that can be stored in an UNSIGNED LONG INT variable is: %lu\n", u_LIntegerVarMax);

    /* exit program after successful execution */
    return (0);
}

'v'

/* examples of characters represented in ASCII */
'b' /* lowercase letter b */
'\n' /* C special character */
'0' /* digit 0 */
' '; /* space */
'B' /* uppercase letter B */

#include <stdio.h>
/**
* main - Entry point of the program 
* Description: Program will print the value stored in a charater type variable
*
* Return: 0 if program successfully executes
*/
int main(void)
{
    /* variable declaration */
    char ch;

    /* variable initialization */
    ch = 'W';

    /* print the value stored in variable ch */
    printf("The character constant stored in variable ch is: %c\n", ch);

    /* exit program after successful execution */
    return (0);
}

#include <stdio.h>
/**
* main - Entry point of the program 
* Description: Program will print the letters of the alphabet in lowercase, 
* followed by a new line.
*
* Return: 0 if program successfully executes
*/
int main(void)
{
    /* declare variable */
    char i;

    /* initialize variable */
    i = 'a';

    /* loop and print the value stored in the variable then increment it */
    while (i <= 'z')
    {
        putchar(i);
        i++;
    }
    /* print a new line */
    putchar('\n');

    /* exit program after successful execution */
    return (0);
}

#include <stdio.h>
/**
* main - Entry point of the program
* Description: Program will prints all single digit numbers of base
* 10 starting from 0 and then a new line.
* 
* Return: 0 if program successfully executes
*/
int main(void)
{
    /* declare variable */
    int i;

    /* initialize variable */
    i = 48;

    /* loop and print the value stored in the variable then increment it */
    while (i <= 57)
    {
        putchar (i);
        i++;
    }

    /* print a new line */
    putchar('\n');

     /* exit program after successful execution */
    return (0);
}

#include <stdio.h>
/**
 * main - Entry point of the program
 *
 */
int main(void)
{
    char ch;
    int num;

    /* Convert an integer to its character constant equivalent */
    ch = 9 + '0' 
    /* Convert a character constant to its integer equivalent */
    num = '3' - '0';

    /* print the values
 stored in the variables */
    printf("The value stored in variable 'ch': %c\n", ch);
    printf("The value stored in variable 'num': %d\n", num);

    /* exit program after successful execution */
    return (0);
}