warning: string literal in condition

I have the same error as you but a different problem, found this through Google might as well post my solution for the next Googler.

I had a typo in my code which also gives the same warning:

if input =! "N"

of course the right way:

if input != "N"

change input == "N" || "n"

to

input == "N" || input == "n"

You must also use else if instead of else

The warning is saying that instead of a boolean or test, you have a string literal, ' n', which always evaluates to true.