Creating an Executable File with the Linker in C++

C++ programs are typically created by linking together one or more OBJ files with one or more libraries. A library is a collection of linkable files that were supplied with your compiler, that you purchased separately, or that you created and compiled. All C++ compilers come with a library of useful functions (or procedures) and classes that you can include in your program. A function is a block of code that performs a service, such as adding two numbers or printing to the screen. A class is a collection of data and related functions; we'll be talking about classes a lot, starting on Day 5, "Functions."

The steps to create an executable file are

1. Create a source code file, with a .CPP extension. 
2. Compile the source code into a file with the .OBJ extension. 
3. Link your OBJ file with any needed libraries to produce an executable program.

The Development Cycle

If every program worked the first time you tried it, that would be the complete development cycle: Write the program, compile the source code, link the program, and run it. Unfortunately, almost every program, no matter how trivial, can and will have errors, or bugs, in the program. Some bugs will cause the compile to fail, some will cause the link to fail, and some will only show up when you run the program.

Whatever type of bug you find, you must fix it, and that involves editing your source code, recompiling and relinking, and then rerunning the program.