The isalpha() function in programming is used to check whether a character is an alphabet or not.
If a character is prove that it is an is an alphabet with the help of isalpha() function in c then it return non zero integer otherwise it gives zero.
This function is define in the <ctype.h> header file in c.
C isalpha() Prototype
int isalpha(int argument);
isalpha() function in c takes a single argument in the form of integer and give an integer value.
Return Value For isalpha() in C
Example Program: C isalpha() function
#include <stdio.h>
#include <ctype.h>
int main()
{
char c;
c = 'Q';
printf("\nResult when uppercase alphabet is passed: %d", isalpha(c));
c = 'q';
printf("\nResult when lowercase alphabet is passed: %d", isalpha(c));
c='+';
printf("\nResult when non-alphabetic character is passed: %d", isalpha(c));
return 0;
}
OUTPUT : -
Result when uppercase alphabet is passed: 1
Result when lowercase alphabet is passed: 2
Result when non-alphabetic character is passed: 0