Thread: traverse a string to look for certain chars

Hey people I am trying to do a validation type thing for the names of people. I prompt for the name and then validate it. I am using getline to store the string because some names contain spaces. i would like to check the string to make sure there are no unwanted chars like "@" and "," etc. so far i can traverse a string to find 1 character using name.find() i will paste the code below, but i cant seem to get that to find more than one char. how do i fix it?

Code:

int main ()
{
string name;
int i = 0;
int dot_appearances = 0;

getline(cin, name, '\n');

for(i = name.find(".", 0); i != string::npos; i = name.find(".", i))
{
    dot_appearances++;
    i++;  
}
cout << dot_appearances;
return 0;
}

So, are you wanting it to find a different symbol other than a period, or just that it won't recognize more than one period?

find_first_of is a good alternative if you want to look for multiple characters at the same time.

I think the for loop would be better replaced with a while loop

while( (i=name.find(".", i)) != string::npos ){ [...] }

I think would do it. Just ++ i just before the end of the loop

well it already finds all the periods in the string. what i want it to do is find other stuff too. so for example if i prompt NAME: d@n T33ry Br0wn
i want to be able to check that string and say its invalid based on the @, 3, 0 characters there. i also do not want to use that find method i pasted because i would have to type out an individual case for each char i want, there must be an easier way

>> i would have to type out an individual case for each char i want, there must be an easier way
That's what find_first_of allows you to do. Put all the chars into a single string, and you only need one loop.

thanks. that find_first_of looks promising. i think i can get that to do what i want.