I work on a new venture at a large enterprise software company (3000+ programmers). In my group, we have a bunch of projects and people usually work on several projects over the course of a year.I just started work on a project that has been previously maintained by a buddy of mine (consultant who's been with us for 3+ years) to add some features. I got into the code, and the quality was really quite poor. Whether it was on the UI frontend or the services backend, the code simply wasn't indented, there were hundreds of lines commented out for no apparent reason, documentation was basically non-existent, coding standards weren't applied consistently (e.g. mixing camelCase and under_scored_variables), variable names were unintelligible, datatype choices were wrong, etc. etc. I'm very much a non-confrontational person, so I don't want to attack my coworker, but I also don't just wanto to go to my boss and complain about his performance. What are the kinds of things I could say to politely mention that the code is poorly structured?EDIT:I want to clarify that while I understand there is an element of Everyone else's code sucks to all programmers, when I see something like this (names are chosen on purpose and some details left out/changed in this example):public void doCalculate(Object argument) {  if (argument instanceof String) {    String argument2 = (String) argument;    if (argument2 == DataBase) {      // do something    } else {      long argument3;      try {        argument3 = Long.parseLong(argument2);      } catch (Exception e) {        argument3 = -1;      }      // do something completely unrelated    }  }}I think it's objectively fair to say that this is not a good idea. Furthermore, I'm not dealing with a newbie here (I'm only coding 3 years now). He's got maybe 20 years of experience on me. The advice you guys have given so far is great; just wanna make sure that we're not talking about a fine line here.
How do I approach a coworker about his or her code quality?
code quality;communication