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I am looking for a function that limit my range? For example, I don't want the user to use two symbols like "^" and "$". So, Instead of using multiples of functions for each element that I do not want the use to use, it will be one function that I put all the odd elements in it. I ddon't know if I make sense to you guys or not..
If the symbols are single ascii characters you could put them in a string and use string.find() to check if the user input a wrong character.
What do you want your function to do, exactly? Do you just want to be able to call ValidInput(string_name) and have it return true/false? In this case, you'd still have to "hard code" in all your characters that are invalid into the function, but if they change you'll only have to change one thing. That's the most obvious thing I can think of, based on the code you've been posting.
I suppose you'd be able to write something like this pseudocode:
Your "for loop" would probably be an iterator over a string.Code:valid = true;
for all bad characters
if bad character found
valid = false
return valid
yeah thanks
Yeah. I am using this function string.find() in some parts of my program.
My point is: I can't use this function this way found12 = y.find('%,^');
the proper way to use this function will be:
found1 = y.find('%');
found2 = y.find('^');
And you know I am not going to limit only these symbols because my program will limit all the small letters, some capital letters, and all symbols. So, you can imagine how waste of time that would be and how big my code that would be..!
*** and once my program detects any of these limitations, I will set a flag for another condition
if y is your string with characters you don't want the user to use, you just need to do something like:
Code:if (y.find(user_input_char) != std::string::npos)
is_valid = false;
This sounds like a job for isupper, which you will have once you #include <cctype>.Quote:
Originally Posted by aama100
And once you've gotten through that, you could do something like this completely untested bit of code which is probably wrong in several ways:
Code:std::string bad_string = "EFRMNTZ"; //or whatever your bad letters are;
std::string::iterator it;
for (it = bad_string.first(); it != bad_string.last(); it++) {
if (y.find(*it) != std::string::npos) {
is_valid = false;
}
}
why use iterators and loops when a simple algorithm like find() suffices on this case? Algorithms were created exactly to simplify many common tasks and consequently reduce code complexity and chances for mistakes.
Because find will only find the exact match of the entire string? The way you have it set up, he has to loop through each input character to find it in the string of bad characters; the way I have it set up, he has to loop through each "bad" character to find it in the string of input. Either way, there's a loop. Edit to add: IIRC, the code is 16 characters long, but he had less than 16 "bad" characters, which is why I went my way instead of your way.Quote:
Originally Posted by Mario F.
Yes. It's possible.
The op didn't clarify when the check is to me made. I'm assuming he's checking every key press. But chances are he's not if he's using cin.
find_first_of may be the STL algorithm of choice here.
What about std::search()?
http://www.cppreference.com/cppalgorithm/search.html