Question

I am trying to write a function which takes a string as an argument and checks if that string contains only one non-alphanumeric character, if this is the case then return true, if not, return false.

For example:

'Alex's' would return true. 
James..Warner would return false.

My current code is below, but I don’t feel that its working. As I have a count elsewhere which basically counts the true’s. Done using a map which contains the strings. And the value which I am getting for the count is too high for the words that are being input.

bool Class3::filter(string word)
    {
        string s = word;
        int len = s.size();

        for (int i=0; i<len; i++)
        {   if(!isalnum(s[i])){
            return true;}
            else{return false;}  
        }
     }

Answer 1

You aren’t counting the number of non-alphanumeric characters in your code, do you? you just return true or false on the first character.

Unless you count, you won’t find the answer. However, you can stop at the second non-alphanum.

Since you seem to need the exercise in writing code, here’s some psuedo-code:

int nonalphas = 0;
for ( char in string )
    if ( char is nonalpha )
        nonalphas++;
        if ( nonalphas > 1 )
            break;
return nonalphas == 1;