Answer:
A good friend should never betray you in any way, talk about you behind your back nor do anything else that questions your friendship. Trust – Good friends should be trustworthy. One should have friends to whom you can be able to tell all your secrets without any fear of them telling other people about them later.
Boo Radley has many purposes. From a plot standpoint, he helped show the innocence of Jem, Scout, and Dill, while ensuring that Jem and Scout survive their run-in with Bob Ewell.