More modern IDEs include the capability to set breakpoints, run from start to the first breakpoint encountered, run from the current breakpoint to the next breakpoint, "single step" through a program (or, if you prefer, "sketch"), examine the contents of variables (and let the user specify variables to display at every breakpoint), and even modify those contents.
there is no debugger for the Arduino.
The AVR lacks some of the "standard" debugging capabilities of many CPUs (ie "single step mode"), and Atmel doesn't document the debugging protocols that the chip does support. :-(
My laptop doesn't have a middle button.I just use CTRL-C & CTRL-V to copy & paste. Haven't gotten used to right-click this & right-click that.
Well, that all works great for debugging a program running on the same machine as the debugger. In the case of the Arduino, the code is NOT running on the PC, and there is no debugger for the Arduino. No keyboard (or output device), either.