How does Karel run without “main” method?

Question

I was wondering in the program like Karel the Robot runs because it does not used main() method. Instead it used run() method:

import stanford.karel.Karel;

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Answer 1

a "main" method is the starting point of every java program. What is going on with this class is that its not a java program by itself, is executed inside some type of framework (karel robot java implementation in this case), this frameworks off course have a "main" method but not this class, the framework knows how to load this class and execute his run method.

This "programs" are frameworks designed to do a specialized type of programs, i don't know this "karel framework", but for example, when you program a java web application you write a "servlet" but you don't write a "main" method. There are some programs called "application servers" that off course have a "main" method and take this servlet class and execute for response to some http message.