isalnum() - Character Function
How is "isalnum()" used in C++?
Explanation
isalnum() is used to check whether the given argument is alphanumeric character (integer or uppercase/lowercase alphabets). This function returns zero when the argument does not have any of them.
int isalnum ( int c );
Result :
Enter a alphanumeric character::
3
Alpha-numeric character
In the above example, this function is used to check if the entered number is alphanumeric. It checks if the ASCII value passed in has a character equivalent to a number of letter.
Syntax:
int isalnum ( int c );
Example :
| #include <iostream.h> #include <ctype.h> int main() { char a; cout << "Enter a alphanumeric character::\n" << endl; cin >> a; if(isalnum(a)) { cout << "Alpha-numeric character"; } else { cout << "Not a Alpha-numeric"; } return 0; } |
Result :
Enter a alphanumeric character::
3
Alpha-numeric character
In the above example, this function is used to check if the entered number is alphanumeric. It checks if the ASCII value passed in has a character equivalent to a number of letter.
