Ytukyg

I want to get a char input and if it contain more than one letter it should print a custom message.
for example 'a' is good 'abc' is not good.
Here's my code

{

    std::cout << "Enter information for your objects" << std::endl;

    const char circle = 'c', quadrilateral = 'q', rectangle = 'r', parallelogram = 'p'; char shapetype;

    char x = 'y';

    std::cout << "which shape would you like to work with?.. nc=circle, q = quadrilateral, r = rectangle, p = parallelogram" << std::endl;

    std::cin >> shapetype;

    switch(shapetype) {

    case 'a':

        //do something

        break;

    case 'b':

        //idk

        break;

    default:

        //doesnt matter

        break;

    }

}

so the problem is when its reading the char if i type for example 'abc'
it gets into the 'a' case.

Thanks!

char check;

std::cin >> check;

You are only reading one character, you can't really guess whether the user typed in more than one letter or not.

It might be a better idea to read a std::string by getting a whole line from std::cin, then checking if the string is really what you're expecting it to be.

Here is an example from std::getline:

#include <iostream>

#include <string>



int main()

{

    std::string s;

    std::getline(std::cin, s);

    std::cout << s;

}

When you type in hello world and press enter, it will print it back the same text.

If you still want to use a switch to check for just a single character you could check if s.size() == 1 then do your switch(s[0]), else fail.

Alternatively, you could do a bunch of if-else over the string, e.g. if (s == "a") { /* ... */ }, etc.

Firstly, you need to understand that a char can ONLY contain a single character. It doesn't matter if the user types an entire sentence, your char shapetype will only end up ever receiving the first character from the sentence they type.

Your main problem I think here is that you're using std::cin and this doesn't validate or care about how much input someone types. All that is going to happen is that the first character that they type is going to end up in your char shapetype variable. That means, to your code, someone typing "a small hole" is exactly the same as if they typed just "a".

So the questions you should really ask yourself are:

• Do you care if the user types more than a single character? If the answer to this question is yes, then you need another approach.




• If you don't care if the user types more than one character, then you can simply do as others have suggested and capture the input into a std::string using something like getline(), check .empty() and .size() for greater than 1 then output an appropriate error message. Other than this, you know you've got exactly a single character. You might want to do a case conversion so that your switch will work with both uppercase and lowercase input too.

Now if you want to just accept a single character you can use something like getchar() that captures a single character only.

#include <stdio.h>



int main(int argc, char** argv) {

    std::cout << "Enter information for your objects" << std::endl;

    const char circle = 'c', quadrilateral = 'q', rectangle = 'r', parallelogram = 'p';

    std::cout << "which shape would you like to work with?.. nc=circle, q = quadrilateral, r = rectangle, p = parallelogram" << std::endl;



    int shapetype = getchar();



    switch(shapetype) {

        case 'a':

            //do something

            break;

        case 'b':

            //idk

            break;

        default:

            //doesnt matter

            break;

    }

}

You need to also take care that getchar() actually returns an int rather than a char. So you might need to perhaps cast it, if needed. However, the above should solve your problem.