Can someone show me how to use isalpha() in an if() condition?

Question

I'm just not sure how to use isalpha() in if() to check if an entire string is comprised of letters. Thanks!

Answer 1

Isalpha takes as an argument a character, it is easy to use a for loop to iterate over each character in a string:

string name = "my name"; // char* name
    for( int k = 0, s = strlen (name); k < s; k++)
        {
            if( isalpha (name[ k ] )) // if( !salpha(name[k])) If it is not
                {
                    code...   
                }
        }

Answer 2

The function isalpha() takes a character as an argument to the function and returns true if character is alphabetic and false otherwise, which thus becomes condition for an statement if(condition), so you can simply use a for loop to iterate over each character in a string and check using if condition, is the ith character in a string an alphabetical letter or not. And be sure to include library ctype.h. Example as follows:

#include <ctype.h>
...
string word = get_string();
for (int i = 0, n = strlen(word); i < n; i++)
    {
        if (isalpha(word[i]))   // here condition is checked is it alphabetical letter for each character in string
        {
            // code...   
        }
        else
        {
            // otherwise code...  
        }
    }