“Multiple definition”, “first defined here” errors

The problem here is that you are including commands.c in commands.h before the function prototype. Therefore, the C pre-processor inserts the content of commands.c into commands.h before the function prototype. commands.c contains the function definition. As a result, the function definition ends up before than the function declaration causing the error. The content of commands.h … Read more

Random not declared in scope

random is not a standard C++ function; it’s a POSIX function, so it’s not available on Windows. Use rand instead, or better, the new C++11 randomness library.

How do I include a JavaScript file in another JavaScript file?

The old versions of JavaScript had no import, include, or require, so many different approaches to this problem have been developed. But since 2015 (ES6), JavaScript has had the ES6 modules standard to import modules in Node.js, which is also supported by most modern browsers. For compatibility with older browsers, build tools like Webpack and Rollup and/or transpilation tools like Babel can be used. … Read more

How do you #include files in java?

You don’t #include in Java, you import package.Class. Since Java 6 (or was it 5?), you can also import static package.Class.staticMethodOfClass, which would achieve some forms of what you’re trying to do. Also, as @duffymo noted, import only saves you from systematically prefixing the imported class names with the package name, or the imported static … Read more

class not declared in scope – even though .h was included

The common circular include problem occurs with:a.h b.h If some cpp includes “a.h” you might get away with it (if b.h didn’t really need a.h). But if that cpp instead includes b.h then b.h includes a.h BEFORE declaring things needed by a.h. Then a.h tries to include b.h but the include guard blocks that, so the compiler … Read more

How do I run a file on localhost?

Ok, thanks for the more specific info, ppl may remove their downvotes now… What you are proposing is a very common thing to do! You want to run your web application locally without uploading it to your host yet. That’s totally fine and that’s what your Apache is there for. Your Apache is a web … Read more

Inserting a PDF file in LaTeX

Use the pdfpages package. To include all the pages in the PDF file: To include just the first page of a PDF: Run texdoc pdfpages in a shell to see the complete manual for pdfpages.

C++ #include guards

The preprocessor is a program that takes your program, makes some changes (for example include files (#include), macro expansion (#define), and basically everything that starts with #) and gives the “clean” result to the compiler. The preprocessor works like this when it sees #include: When you write: The contents of some_file almost literally get copy pasted into the file … Read more

C++ #include guards

The preprocessor is a program that takes your program, makes some changes (for example include files (#include), macro expansion (#define), and basically everything that starts with #) and gives the “clean” result to the compiler. The preprocessor works like this when it sees #include: When you write: The contents of some_file almost literally get copy pasted into the file … Read more