Why I can't debug this code and how to resolve "undeclared identifiers" mistakes in .h FileTools class file. Task and code below

Question

I need it to be solved with C++. The task itself is below.

Even though it seems that I wrote a right code, since there are no highlighted errors, I cannot debug since there are like 50 errors. Almost all of them in the .h file and about undeclared identifiers.

Write a program to analyze a file and display various statistics about it. The analysis should be
performed by a class called FileTools, which accepts the file name of a file to analyze via its
constructor, and has the following member functions:
- process() – reads the file and contains statistics about the number of lines, total number of
character

https://code.sololearn.com/carstqIRhyn0/?ref=app
https://code.sololearn.com/c0q9mZ6gqxbp/?ref=app

Answer 1

I removed all invalid characters and edited the code. Now it works without any error on my part

https://code.sololearn.com/cgWlrbqI0c18/?ref=app

Answer 2

When I open the full driver code file I got some error messages pointing out that there are 'extended characters' in the code.

Seems like your code gets some invisible & invalid characters that prevents the compiler from compiling the code. It happens mostly due to copy/paste of text/code from browser or other app which uses those characters for formatting etc.

You can see the characters if you open the code in web, not SoloLearn app.

Answer 3

Yep, it's working. Thank you

Answer 4

I don't think that's the case because I just wrote the whole code again with copy/paste, and it is still not working. 46 out of 50 mistakes that are shown to me in VS connected to FileTools.h file, and the majority of those 46 mistakes are about undeclared identifiers.

¯⁠\⁠_⁠(⁠ツ⁠)⁠_⁠/⁠¯