In a recent post to his site James Cowie sings the praises of Xdebug for debugging and says that "var_dump must die" as a method for debugging in your application development flow.
How many times have you been working in Magento or any other php application and hit an error, exception or something not quite right? For me a lot. I’ve been that developer that debugs by fire and throws echo var_dumps and dies around like a western gunslinger. It’s easy, provides quick feedback cycles but lets be honest its lazy, in efficient, rarely provides all of the data you need to solve the problem on the first try and its not something you want to boast about by the coffee machine.[...] So whats the “better” way of debugging a application? Well welcome Xdebug + PHPStorm. Imagine inside of the IDE we can set a breakpoint, a fancy die and reload our web page. Magically the IDE has stopped execution and we can see the state of the application at that exact path. We can see the variables and we can step through the code and see exactly what class and method is called next and so on and so forth.
While his instructions are specific to PHPStorm, most major IDEs will have a similar setup process with their own tweaks. In his case, though, he has one more layer of complexity - the PHP is executing inside a Docker container. He walks you through the process he followed to get the flow from container to local IDE set up. He wraps up the post with an example of debugging a script and what the results look like inside of PHPStorm (including a screencast).