I am new to flutter, was going through a few good practices so had a doubt about making all the functions and variables private which won't be used outside the class.
2 Answers
take a look here. https://dart.dev/guides/language/effective-dart/design#prefer-making-declarations-private
refereeing to dart.dev/guides its good to use private variable because they said
"PREFER making declarations private. A public declaration in a library—either top level or in a class—is a signal that other libraries can and should access that member. It is also a commitment on your library’s part to support that and behave properly when it happens.
If that’s not what you intend, add the little _ and be happy. Narrow public interfaces are easier for you to maintain and easier for users to learn. As a nice bonus, the analyzer will tell you about unused private declarations so you can delete dead code. It can’t do that if the member is public because it doesn’t know if any code outside of its view is using it."
But here's the thing, it all depends on your need, but remember to make security concern. It's not wrong to use private variable all over the place if you doesn't want other class access your variable, function or class.
It depends on the variable usage because if you are not going to use the variable outside of the widget then you should keep it private (Good practice [In my opinion]) otherwise make it public.
Making private is good because you can avoid variable conflict because sometimes you may have the same name variables in different widgets so if they are private then they will not conflict with each other.
Same for the functions as well.
-- This is my personal opinion you have the freedom to make your own decisions which to use.
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