To use LogCat you need to import the Log library in the java code import android.util.Log;
Then, where you would normally print something, replace “System.out.println(“HERE”);” with:
Now when you run your app on the emulator or a device it'll print out to logcat, which can be viewed right in Eclipse (might need to go to Tools and click LogCat or something similar) or in the terminal in the directory where the android sdk has been installed, in the <sdk>/platform-tools/ folder.
Run adb logcat from that directory location to view the logs.
This prints out a log of everything that's happening, so if it's on the phone there's probably going to be a lot of stuff going on continuously, which is why it's helpful to use good tags so you can just browse or search for "LOGCAT" and you'll find what you're looking for.