In C programming, a character variable holds an ASCII value (an integer number between 0 and 127) rather than that character itself.
The ASCII value of the lowercase alphabet is from 97 to 122. And, the ASCII value of the uppercase alphabet is from 65 to 90.
If the ASCII value of the character entered by the user lies in the range of 97 to 122 or from 65 to 90, that number is an alphabet.
Program to Check Alphabet
#include <stdio.h>
int main() {
char c;
printf("Enter a character: ");
scanf("%c", &c);
if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
printf("%c is an alphabet.", c);
else
printf("%c is not an alphabet.", c);
return 0;
}
Output
Enter a character: * * is not an alphabet
In the program, 'a'
is used instead of 97
and 'z'
is used instead of 122
. Similarly, 'A'
is used instead of 65
and 'Z'
is used instead of 90
.
Note: It is recommended we use the isalpha() function to check whether a character is an alphabet or not.
if (isalpha(c))
printf("%c is an alphabet.", c);
else
printf("%c is not an alphabet.", c);