Declaring a char pointer

April 19, 2022

I’m trying to make a login/register project and I have difficulties in declaring the char* tempUsername from this code (SIGSEVG segmentation fault)

char *tempUsername, *tempPassword, *tempPasswordConfirm, *tempSecurityQuestion;

/*
no other declaration for tempUsername here
*/

std::cout<<"Enter your new username:\n";
std::cin>>tempUsername;

//process stops here

        if(fileSearch(newFilename(tempUsername))) {
            std::cout<<"Username already exists! Choose another username!\n";
        }
        else {
            std::cout<<"Enter your password:\n";
            std::cin>>tempPassword;
            std::cout<<"Confirm your password:\n";

I’m having a hard time understanding anything about pointers, so any advice is more than helpful!

>Solution :

char *tempUsername

std::cin>>tempUsername;

The problem here is that your pointer is uninitialised. When you try to extract from the input stream into the uninitialised pointer, the behaviour of the program will be undefined. Don’t do this.

Your goal seems to be to read a string of user input. A solution that I can recommend is to use the std::string class:

std::string tempUsername;
std::cin >> tempUsername;

No need to use a pointer to achieve this.

I can use a char* as an array of chars, is that true?

It is not true in general. If you have a char* that points to an element of an array of char, then you can use that char* as an iterator to access the elements of the array.