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How do I determine if a char in C such as a or 9 is a number or a letter?
Is it better to use:
int a = Asc(theChar); or this?
int a = (int)theChar 
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C isalpha() The isalpha() function checks whether a character is an alphabet or not. In C programming, isalpha() function checks whether a character is an alphabet (a to z and A-Z) or not. If a character passed to isalpha() is an alphabet, it returns a non-zero integer, if not it returns 0.
isalnum() is a built-in Python function that checks whether all characters in a string are alphanumeric. In other words, isalnum() checks whether a string contains only letters or numbers or both. If all characters are alphanumeric, isalnum() returns the value True ; otherwise, the method returns the value False .
A char is not an object, so you can use equals() like you do for strings.
You'll want to use the isalpha() and isdigit() standard functions in <ctype.h>.
char c = 'a'; // or whatever if (isalpha(c)) { puts("it's a letter"); } else if (isdigit(c)) { puts("it's a digit"); } else { puts("something else?"); } chars are just integers, so you can actually do a straight comparison of your character against literals:
if( c >= '0' && c <= '9' ){ This applies to all characters. See your ascii table.
ctype.h also provides functions to do this for you.
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