Comparisons in C VS VB

Question

Here is the C code:

do
{
    printf("\nOver eighteen (Y/N): ");
    scanf("%c", over18);

    if(over18 != "Y" || over18 != "N")
    {
        printf("\nInvalid input");
    }

}  while(over18 != "Y" && over18 != "N");

Hey, I am new to C and I am trying to sort-off translate my old VB code from when I was learning that into C. I have attempted to do that for this part of a program, but that gives the error "warning: comparison between pointer and integer" for all my comparisons using ".=".
Here is the VB code:

    Do
        Console.WriteLine("Are you over eighteen (Y/N)?")
        over18 = Console.ReadLine()

        If over18 <> "Y" And over18 <> "N" Then
            Console.WriteLine("That is not a valid answer")
        End If

    Loop Until over18 = "Y" Or over18 = "N"

Why is this happening?

Answer 1

In C, strings are just arrays of chars, which translates into a char pointer.

So, to compare strings, you must use the function strcmp .

Your code should then be the following

strcmp(over18, "Y") != 0