ralph | Ralph is a Lisp-1 dialect that compiles to JavaScript | Interpreter library

I have a C++ program with an undefined reference error on the call of a method in a class. As near as I can tell, the method is public and I'm calling it with a parameter declared the same as the method definition, but eclipse/gcc tells me it is undefined. I'm not used to C++, can someone please tell me what's wrong with the definition?

The main class:

I have a large amount of books and I want to build a database to manage them. My idea is to scan all their barcodes, put them in Google Sheets then use OpenLibrary API to retrieve the corresponding meta data (title, authors etc.) to avoid typing it all in.

The API structure is simple enough and I'm able to retrieve the information by passing over the barcode (ISBN number):

I have been learning dart but having some issue with the below code in which I have used default constructor to avoid taking default values inside the class as a practice but the compiler says that it is must to initialize class variables as those values can't be nullable. Is it really needed to assign class properties if my default constructor is assigning those values while initializing objects of class in the main ? Kindly help on this.

i have 3 tables

I am trying to making a python autogenerated Email app but there is a problem when running the code the traceback error shows up but I did write the code as my mentor write it down. This is the code that I used:

I am using Files.walkFileTree() on a Windows 10 Pro system, and prints an exception stackTrace on some files. I'm trying to figure out how to determine what files will throw this exception before it is thrown; so far none of the files that cause the error are interesting to me, but I want the program to be able to detect which files would throw the error before it's thrown.

code:

I am trying to use Try/Except in order to scrape through different pages of a URL containing author data. I need a set of author names from 10 subsequent pages of this website.

I would like to display a data from .txt report file using JavaFX. In my code, I'm trying to use Labels and Vbox to display the info in multiple formats in a GUI to scene. However, I'm having terrible outputting my results as GUI instead of the console. I tried to research my issue but I couldn't find the piece of info that I need to solve the problem.

This is the report I need to display as a GUI Application using JavaFX:

This is what my code displays as a GUI:

Here is my source code:

I have a question that sorts data from a car report of txt file.

The question is: How do I listed cars sorted by their MAKE (Ford, Chevy ..etc). They only need the MAKE to be sorted so they can be all FORD cars under each other, then Chevy, DODGE .. so on and so forth like this:

And this is what I have so far:

Here's my source code: