Learning notes from a C++ n00b – Part 1
I am primarily a Java developer. My college decided in my sophomore year to switch from C/C++ to Java for most of the classes. While it did give me a very good foundation in Java development, it created a bit of a gap in my education. While I’ve done work in C in the past, I haven’t had the opportunity to work on a serious project in C or C++. Since my goal is always to learn a language a year, starting now C++ will be that language. It should be exciting.
This post is the beginning of a series describing my process of exploration and discovery into the wonderful world of C++ from the perspective of a Java programmer. I imagine that some people who know C++ and Java are getting out popcorn waiting for the inevitable meltdown with dealing with things like memory leaks, makefiles, platform differences, and probably a bunch of other common issues I know nothing about. While that may eventually be the case, I’m not there yet.
Immediately, one of the biggest departures between Java development and C++ development is the change in IDE. For Java development I’m a big fan of IntelliJ IDEA. Java has a lot of import statements that involve very long package names and an IDE like IDEA tends to take care of that for you. Refactoring, like changing method or class names, is easy since I don’t need to manually find all usages and change them. Autocomplete and click jumping to method or class definitions is also very handy. The integrated debugger is useful when needed, and I like that it can easily import maven pom files as projects. While I’m definitely a proponent of being able to program in your language without an IDE (you shouldn’t let your IDE program for you), it still can be a useful tool at times.
My new IDE for C++ is vim. Ok, I don’t know if I’d really call it an ‘IDE’ exactly, but it’s my editor. I like vim overall, and I’ve been an avid user of it for about 7 years, so I can maneuver my way around. After reading about ctags, I wrote a script to generate them so that I can use it to jump between functions and methods. I’m pretty sure I’m not using it correctly however, as I have a tags file in each directory and I think the editor doesn’t always pick up all of the tags files I want. I have no idea how to use a debugger, and dealing with import statements is still a pain. Overall though vim is very fast and never hiccups unlike IDEA, so that’s a plus.
Another large departure from Java development is going from maven to makefiles. In Java I can create a maven pom.xml file to list all of my dependencies and plugins. Maven supplies a natural file structure that I can use to arrange my files into packages and place external resources in a place where the classpath will pick it up. There are tools to automatically create stub maven projects that I can just jump into and start coding. I can have any tests in my test directory automatically run just by calling mvn test. I can compile my project using mvn compile, and I can package it all up into a nice jar or war file by using mvn package. These are all default things that come with maven. It takes care of running the javac command to compile my code. It also sets up a testing environment for running tests. A very handy tool.
So makefiles. Makefiles sort of remind me of ant. I never really got into ant because it’s fairly verbose. It requires you to be more explicit in telling the system what to do and how to do it. Really though, makefiles are a bit less useful than ant, as they seem to be more like elaborate shell scripts that use the make utility to run. I still have to put in all of the g++ commands, along with lines of what libraries and other sources to give to the linker. Dependencies have to be accounted for manually. Tasks like clean or test have to be defined along with instructions for what those things actually do. There is no standard setup with clean interfaces for running tests or setting up your file structure. The main positive aspect that makefiles have over maven pom files is that a single makefile can generate several different deliverables (pom files only create a single jar).
I know that there are tools such as autoconf and automake that is supposed to make makefiles more portable to deal with library issues, but they’re not very easy to use. The GNU tool chain has a fairly extensive manual, but it feels like one needs to read the entire thing before even getting started. I haven’t had the time, so the GNU tool chain hasn’t entered my arsenal yet. I’m still not sure how to deal with the library distribution issue, but I’m sure that will come with time.
I’ve only been really looking deeply into C++ for a week or two now, and there are a lot of questions that pop into my mind. I have certain philosophies dealing with programming that I’ve gained over the years. A lot of those practices have been fueled by ideas from the Pragmatic Programmers. Others I have developed on my own. I’m still uncertain as to how to incorporate some of these ideas in my C++ development.
The first and most important of these is unit testing. Java has some very standard unit testing frameworks with JUnit and TestNG. Boost has a library for unit testing C++, and so does Google Test, but I have yet to delve into either of these deeply. Also I’m not sure if there’s a standard way of running tests like you can find with Java. Making sure that each test is in its own section in a makefile doesn’t seem very appealing. Hopefully I’ll find a nice way to easily unit test code (including using mocks), I’m just not there yet.
Also, how do you profile C++ code? I’ve used a tool called yourkit for Java which works very well. I know that there must be profilers for C++, but I don’t know what they are or how to use them. Similarly, debugging is an area that is still very grey. I know that there’s gdb, but I haven’t found a good tutorial on how to use it or how to integrate it into vim or some other editor to set breakpoints and see variable values.
And honestly, while I understand the basic concepts of pointers, I’m still unsure as to when to use them and how to fully utilize their functionality. In Java everything is done by reference (except primitives) and there’s a garbage collector when items go out of scope. When passing any object to a method, it can be modified by that method. I still need to learn a bit more about how scope effects both objects created on the heap and other objects in C++.
Overall there has been a lot of learning in the short time that I’ve been playing around with C++. While I’ve used Objective-C in the past for some iPhone programming, I haven’t really seriously taken on any projects in C++. The learning experience has been great, and quite a bit of fun. While most people would probably argue that makefiles are really annoying to set up, I’ve been enjoying the learning process of figuring out how to use them and creating working builds. My tests have all been small at this point, but they’re sure to grow in size. That said, I know I still have a lot to learn. I shall be delving deeper into the Boost libraries and doing multi-threaded programming with some asynchronous socket connections. I’ll be sure to update again after having gained a bit more experience.