Debugging is the process of finding and reducing the number of bugs in your application. In the past, it was a fairly complicated process, sometimes requiring external tools. Today, most programming environments have an integrated debugger, an easy and enjoyable way to find errors in your code. In this chapter, we will focus on the integrated debugger. Out of the box, IntelliJ IDEA supports debugging for Java, Groovy, and JavaScript applications. The debugging functionality is incorporated in IntelliJ IDEA; you only need to configure its settings. Depending on the enabled plugins, the IDE can also support debugging for other languages, for example, Scala or PHP. We will begin by reviewing the debugger settings and options. Setting up the Java and JavaScript debugger will give you a general idea of how to set up the debugger for the language of your choice. Next, we will look at the debugger tool window and then go to the debugging process itself. At the...