Answer :

#include<stdio.h>   //header file contains the function,decleraction and macro defination of key words used in code.

int main ()

{

char a;   //adressing the variables

printf("Enter any alphabet or a number you like\t");  //output

scanf("%c",&a); //stores the input from the user

if (a>=97&& a<=122 || a>=65 && a<=90)  //condition

{

printf("%c is an alphabet",a); //output

if (a>=97 && a<=122)

{

a=a-32;

printf("The character is converted into upper case is %c",a);

}

else

{

a=a+32;

printf("The character is converted into Lower case is %c",a);

}

}

else if (a>=48 && a<=57)  //condition

{

printf("%c is number",a); //output

}

else 

{

printf("%c is a symbol",a); //output

}

}

Output :