A character is entered through the keyboard. Below is a program to determine whether the character entered is a capital letter, a small case letter, a digit or special symbol.
We will make use of isupper(), islower() and isdigit() functions to write this C Program.

isupper() – This function will take character as parameter and will return true if the character is UPPERCASE.
islower() – This function will take character as parameter and will return true if the character is lowercase.
isdigit() – This function will take character as parameter and will return true if the character is a digit else it will return false

Here is the program:

#include
#include

void main()
{
char ch;
clrscr();
printf("Enter a character = ");
scanf("%c", &ch);

if (isupper(ch))
{
printf("Character is in Upper case\n");
}
else
if (islower(ch))
{
printf("Character is in Lower case\n");
}
else
if (isdigit(ch))
{
printf("It is a digit\n");
}
else
{
printf("Special Symbol\n");
}
getch();
}